Another fill for the kinkmeme, but this one's going to be pretty long.

Before I start, I'd like to warn you that if you are at all uncomfortable with elements of cuckolding, non-con, dub-con, heavy smut, and cheating, please turn back now. I have thick skin and I don't mind if you flame me, but I don't want to ruin other people's impressions of the characters just because they read this fic. To some, this story will seem completely out-of-character and unbelievable, and I'm fully aware of that. If you do decide to read this, please keep in mind that I don't hate any of the characters; in fact, it's quite the contrary, as I love every main character in the Mass Effect universe. I'm just taking a little too much liberty with Bioware's characters to explore concepts that I personally don't like, but intrigue me.

The general idea behind the fic is the following:

Tali is in a relationship with MShep. They're very happy together.

However after a couple drinks and some skillful seduction from Garrus, she ends up cheating on Shepard with him. Tali resolves to never let it happen again, but Garrus has different plans.

He uses this one act of infidelity to blackmail Tali into having sex with him whenever he wants. Tali is horrified, but deep down in a place in her mind she would never admit existed, she cant help but be incredibly turned on by the idea.

Bonus points for some humiliation on Talis end.

Super bonus points if Shepard never finds out, and this pattern continues for a long long time.

Consider yourself warned.

Thank you to my wonderful beta for fixing all my horrid mistakes.

Unfaithful - Chapter 1

Tali checked the time on her omnitool, arching her back in a stretch to loosen up the kinks that had settled in from hours of pouring over her console. Even though she was technically on shore leave, she'd still been working all day, in an effort to get the engines back up to speed. Adams, Donnelly, and Daniels were good at what they did, but she knew the Normandy's drive core inside out, and they sometimes missed the little details that she could see. It gave her plenty to do, perhaps a little too much, if skipping shore leave to do some tinkering was any indication.

She popped the joints in her wrists, which were stiff from all the typing she'd been doing, and then the ones in her neck, sighing in pleasure as the tension fell out of them. She powered down her console and brought up her omnitool interface again, tapping the message icon and frowning as it took longer than expected; she'd have to mod it to work faster again, the darned thing. Her inbox was flooded with messages from members of the flotilla (most of it was fan mail, which was partly amusing and partly humbling) and from those aboard the Normandy. She scanned quickly for a message from Shepard, and found none. Well, he had been busy doing errands today, so she didn't blame him all that much. He was as bad as she was when it came to concentrating only at the task at hand, and anyway, she'd have her time with him tonight. She skimmed through messages from Kaidan and Liara, welcoming her aboard, and giggled at one Javik had sent her, seemingly by accident, grumbling about how primitive their communication systems were.

Her thoughts were interrupted by the buzzing of the intercom above her, making her jump.

"Tali, you there?" Garrus' voice filtered through the speaker, slightly distorted.

"Garrus! Yes, how are you?" She hadn't had many opportunities to speak with her old friend since coming aboard, and she had missed his company dearly over the past few months.

"Oh, not too bad, you?"

"I'm fine," she replied, looking up, though she knew he wouldn't be able to see her. "Did you need me for something?"

"Nah, just wanted to know what you're still doing on the ship. Shore leave applies to quarians too, if I remember correctly," he said, a teasing lilt in his voice that made her smile despite herself.

"I was convinced it applied to turians too, though I guess I was wrong about that. Too busy calibrating, hmm?" she giggled as he groaned over the intercom.

"We'd be lucky to hit anythingwith these guns if it wasn't for me, you know."

"Sure, sure. I'm starting to believe Kelly when she said you'd been calibrating your own gun in there all the time."

"Wouldn't you like to know?" he replied, not missing a beat. She spluttered slightly, then managed to gain back her composure.

"That's not what I meant!"

"Mmmmm... if you say so..."

"You are insufferable, Vakarian." His pleased laugh echoed through the drive core room, and she shook her head. Garrus would never change, but that was one of the things she liked about him. He was a constant, always consistent and loyal, while everything else changed. She knew Shepard felt the same way; it was probably the reason their friendship was so strong.

"But listen," he started, bringing her attention back to him. "Shepard's gone to see the asari councillor today, he won't be back anytime soon, and I think we both need a break from watching screens."

"Oh? You have something in mind?"

"Always, Tali. You still owe me drinks for beating you in that kill competition back on Aite, remember?"

"That was months ago!"

"And you never paid up because your boyfriend got himself thrown in the brig."

"That wasn't Shepard's fault," she grumbled.

"I know, I'm only teasing. But really, put work aside for a night."

"I don't know..." she mumbled, twitching the corner of her mouth downwards.

"Come on," he drawled, a hint of challenge in his voice. "It'll be fun."

She sighed. She would never admit it to him, but there was something about that persuasive voice of his, something that she was sure most of the other women on the ship found as attractive as she did.

"Fine," she said, doing her best to sound reluctant. "Give me an hour to finish things up."

Tali squinted as bright lights bombarded her faceplate. Clubs weren't really her thing, as she much preferred the quieter, peaceful areas of the Citadel, but Garrus seemed completely in his element. He'd worked in C-Sec though, she reminded herself. He'd probably be comfortable on any part of the station.

She took his lead as they wove their way through the crowds to the bar, where they managed to snag a couple of seats near the end. The place was packed, though Tali wasn't surprised; people needed some way to forget that there was a war going on, after all. Thankfully the lights were a little less flashy in this corner of Purgatory, so she felt more at ease as she settled into her chair beside Garrus. He signaled over the asari bartender who gave them a warm smile and took their orders. She ordered filtered brandy for herself, and he had a whiskey. Interesting, she thought. She never figured him for a whiskey kind of person. The asari left two glasses in front of them momentarily, a straw floating in hers. She'd probably get a cold for drinking in this unsanitized place, but she would live through it.

"A straw?" Garrus asked, slightly incredulous, as he gestured toward the blue one in her glass.

"I'm not putting it through my feeding tube," she replied with a scoff, lining up the straw with her breathing slot and taking a sip. She resisted the urge to grimace at the awful taste. She didn't much like alcohol, but she'd be damned if she gave Garrus the opportunity to make fun of her for getting something a little more pleasant.

She should have known though that he'd catch her little shudder. "Too strong for you?" he asked with a laugh.

"It's fine."

"Let me guess, you're a lightweight too."

She huffed in reply, refusing to acknowledge the truth in his comment.

"You bosh'tet. Don't you have anything better to do than tease me all the time?"

"Of course not," he replied lightly, shooting her a grin. "It's too easy."

"I could say the same about you, Vakarian," she countered.

"Oh, you don't know that." He looked straight at her then, and she was slightly struck at how blue his eyes were. She'd never really seen them this up close before, and after a moment of staring she blinked and looked away. Garrus let out a laugh and she turned away, feeling her skin flush at being caught staring, but apparently that wasn't what he found so amusing. "So you do want to know? Shepard won't like this."

She let out an half-mock, half-indignant huff, then turned to glare at him, but he was looking out over the crowd again.

"Keelah, you are impossible. I don't know why Shepard keeps you around."

His head turned quickly to look at her, an unreadable emotion in his eyes, but that flickered out within a second as his face softened into an amused expression.

"Your drink's finished."

She looked down into her glass, and sure enough, it was. He wasn't even half done his, and she felt slightly embarrassed for drinking so fast. Garrus didn't seem to take notice of it though as he waved the bartender over, ordering her another drink.

"Thanks," she said, taking another sip. It was burning less now, though she presumed it had something to do with the buzzing feeling in her head. She needed to get a hold of herself, last thing she needed was to get completely drunk with Garrus. He'd never let her live it down.

"Not a problem. So, about Shepard..."

"What about him?"

He shot her a sidelong glance, mandibles spread in a grin. "How do you two make it work, anyway?"

She took another sip, trying to think clearly despite the growing fuzziness in her head. "Why?"

"Oh, just curious. Never tried the interspecies dating thing myself." This caught her by surprise. She'd always assumed Garrus was a little... adventurous in his endeavours.

"Not even asari?" she asked.

He shook his head and quirked a mandible. "Not my type."

"Well, what is your type?" A strange look came over his face, but before she could blink it was gone.

"That would be telling." She laughed and shook her head. He drained his glass, but didn't order another one, instead focusing his full attention on her. "So, Miss Vas Normandy, I believe I asked you a question."

"Let's not talk about that," she mumbled, looking away from him. The intensity of his gaze was a little too much for her. She was nearing the bottom of her glass for the second time; she really needed to get a hold of herself.

"I won't tell anyone, I promise." He did that grin again, and for some reason it made her suit feel a little too clingy, like she'd been running on a hot day.

"We're... careful," she said almost inaudibly.

He leaned closer to her. "What? I didn't get that."

"I said we're careful." He was close enough that had she not had her suit on, she'd be able to feel the heat radiating off of him. It should have felt uncomfortable, but for some reason it felt fine, almost good. She pushed that thought out of her mind quickly though. What the hell was she thinking? She wasn't supposed to be attracted to Garrus, of all people; he was Shepard's best friend, after all.

"Hmm," he hummed, then looked down at her glass again. "Done again?" he said with a laugh. "Let's get you another one."

"Garrus, I don't think that's -"

He waver her objection away. "You'll be fine." He signaled for another drink, and the asari slid a filled tumbler over to him. He gave her a nod and exchanged the new glass for the one still in Tali's hands.

"You're going to be the death of me," she muttered, but didn't hesitate to take a quick sip. She couldn't even feel the burn of it going down her throat now, just a pleasant buzz in her head. Everything felt marvelous, though that might have just been due to Garrus' close proximity. She stifled a giggle and bit her lip.

"No, I'm going to be the one who hauls your drunk ass out of here," he said with a laugh. His eyes met hers again, with an intensity in them that overwhelmed her, but in an oddly pleasant way. "So Shepard's the only one, hmm?"

"I - well, yes, other than another quarian..." He raised his eyeplates at her.

"No turians? I'm surprised."

She choked on her drink, but his gaze didn't falter. He pressed a hand against her arm in a gesture of support, then retreated it when she could breathe properly again. She'd be lying if she didn't feel a pleasant but guilty jolt from the action. "I don't know many turians," she said, trying and failing to keep an even tone.

"Hmm." He tilted his head. "You're missing out." I

She blinked again, trying to find some semblance of rationality in her now thoroughly-tipsy brain to form a reply. Of course, she failed miserably, and chose instead to not reply.

"There are a few ways that turians are more pleasing than humans," murmured Garrus, his voice softly caressing her shaky nerves. "Or so I've heard."

"...Huh," she mumbled, a more coherent response eluding her.

He hummed lightly. The sound was rather... alluring. She couldn't figure out whether he knew how pleasant his voice was or not; he_ certainly knew how to use it to his advantage though. "We like to give, more than receive." His voice was low in her ears, which sent a shiver down her spine.

"I, uh..." She had no words; her mind was an utter blank. She fidgeted with one of the buckles on her thigh with her free hand.

"You look lovely when you're embarrassed, you know," he said softly, and her eyes went wide as she met his gaze again. The look he was giving her made her knees weak. He placed a hand on her knee, and she had to make a conscious effort to keep the glass from falling out of her hand. He held her gaze for a while, as his face relaxed into an expression that was unreadable, but at the same time unbearably attractive. The intensity of it made her want to look away, but she couldn't make herself do it. The tips of his fingers skirted back and forth on her kneecap, making her blink in nervousness. How had he managed to reduce her to a blubbering mess like this?

"Am I making you nervous?" he asked gently, though without any hint of self-doubt. If anything, he sounded slightly smug.

"No," she mumbled, though it wasn't entirely honest. She didn't mind, far from it really, but his closeness did make her nerves jitter in excitement and tension.

"Good," he purred, "because I don't think I could pull away from you if I tried." He looked down to where her mouth was; this close up he would be to make out the outline of her lips under the mask, which is where his eyes lingered now, then went back up to look into her own. He wanted her, she realized, oh Keelah, he wanted her. She found herself leaning forward toward him unconsciously, into his touch.

"Why's that?" she managed to say.

One of his mandibles quirked into a crooked smile. "Well, you are quite the woman Tali." He breathed her name in a way that made her heart race. She swallowed thickly as his scent filtered into her helmet. It was utterly alien, fresh and natural with a tang to it, bewitchingly foreign. The muscles in her legs tightened as she felt the twinge of arousal in the pit of her stomach. This wasn't supposed to be happening, she wasn't supposed to be attracted to someone other than...

His hand trailed up her thigh, stopping halfway up. She could feel the heat of his body now, impossibly close to her; how was he still sitting down? Nothing made sense in her head through the haze of alcohol and lust. "I..." she began, but his mouth brushed against the arch of her neck over her suit, and it made any semblance of thought disappear from her mind.

"Feel like staying?" He murmured, his flanging voice tightening the knot of excitement in her stomach. Desire curled and uncurled within her, its traitorous tendrils wrapping around her mind and seizing hold.

"N-not... really. What were you thinking?" She felt his mandibles flare into a smile, just as he pulled back slightly to look her in the eyes again. Thinly veiled lust was reflected in them, and it just made her grow hotter under her suit.

"There's a nice hotel close to here."

"Okay..." she breathed, as he plucked the glass that hadn't fallen out of her hand by some miracle and placed it on the bar, along with his credit chit. Garrus pulled away further, but didn't move the hand on her thigh. Once the bartender had rung them through, he stood quickly and wrapped a hand around her waist, pulling her off the chair. She had a bit of trouble walking, but he held her up and steered them out of the place swiftly. Despite her better judgement, she was thrumming with arousal and excitement, but there was a twinge of guilt mixed in that she simply couldn't shake off.

Shepard would never find out about this. Yes, she'd make sure of that.

The hotel he'd picked was actually very tasteful, but once the door closed behind them she didn't get time to admire the view or the bathtub. Before she could think, he'd pinned her against the wall with a surprising show of force, though he was careful not to hurt her. His body pressed up against hers, and she writhed slightly underneath him, her body betraying her need for contact with his. His hands explored her body feverishly as she traced the angles and plates of his face, her own hands trailing up and down his fringe. His fingers eventually found themselves close to the clips of her faceplate, and he managed to undo one before she pulled away.

"I can't, I'll get -"

"Sanitized suite," he grunted, then pulled off the mask. She gasped_ as the warm air hit her skin, feeling utterly foreign. Garrus was studying her with a mix of awe and curiosity; he clearly hadn't seen an unmasked quarian before. She suddenly felt very self-conscious and turned her head away, but he pulled her back to face him. "Don't," he murmured, more gently this time. "You're beautiful."

She didn't have time to ponder the odd harmonics of his voice as he leaned forward, dragging his tongue from the base of her neck to her ear, gently nipping at the flesh. The effect of the alcohol had worn off a bit, but he was overwhelming her with the sensations he was creating. His fingers worked on the straps of her suit while his tongue explored her exposed skin, coaxing moans from her.

"Keelah," she whispered, as he traced her collarbone with small nips. His fingers were still struggling with the straps, so she pushed them away and undid them herself. She unbuttoned the pieces of her hood and helmet and let them fall to the ground haphazardly, letting her hair spill out in a tangle. He didn't wait even a moment before weaving his fingers through it, leaving butterfly kisses on her skin with renewed vigor. She somehow managed to keep undoing the buckles and zippers as he continued to touch and lick her; she shivered a little every time his caresses touched her bare skin.

His hands followed wherever she peeled off her suit. She managed to take off the last pieces on her chest and shoulders, baring pale skin to open air. He pressed her into the wall, his cold armor chilling her as he pushed harder against her. He ghosted his gloved hands over her humble-sized breasts, teasing her with barely-there touches. She moved closer to him, arching her back as her body ached for more, his eyes watching her closely. She felt wet heat building between her legs, making her muscles tighten with need and anticipation.

"I need you," he rumbled lowly into her ear, making her breath waver.

"I, Garrus, please..." He rubbed her nipple with his thumb, making it pebble, then bent down down and ran his tongue over it. She wouldn't have been able to hold back the moan that escaped her mouth even if she tried. Her fingers fumbled along his armor, haphazardly undoing clasps and buckles as she came across them. She pulled off any pieces she did manage to undo as he nipped her shoulder softly, then licked the imprints he'd left on her skin. One hand gripped her breast more firmly, while the other pulled her hips flush against his.

"What?" He almost growled into her ear, running the tip of his tongue over her bottom lip. He didn't give her the opportunity to reply though, for when her lips parted he slipped his tongue into her mouth. She pressed against his mouthplates, drawing him further into her mouth as he took the chance to explore. Their tongues teased and played, slowly at first, then frantically as they both grew more feverish.

Eventually she managed to undo most of his armour and pull it off, leaving his upper half in just his undersuit. She searched for the zipper in a sort of lust-induced frenzy, eventually finding it and nearly ripping it off. He helped her pull it off his shoulders, leaving the bare expanse of his plates open for her to discover. She pulled away from their kiss to suck on the tip of his mandible, drawing a groan from him as her nails raked down his cowl. "I want you inside me," she managed to finally say, which made him pause for a moment.

For a brief second she thought she'd said something wrong, but it was quite the contrary, she found out, when he picked her up by her thighs and wrapped them around his waist in a rather impressive show of strength. She kissed him again as he walked them over to the bed, stumbling every so often when she ran her fingers over the sensitive spots on the back of his neck. They fell in an unceremonious heap on the bed, both refusing to let go of the other. His hands removed the remaining pieces of armor he had on, throwing them at the foot of the bed, until only the undersuit covering half his body was remaining. She reached up and locked her ankles behind his back, pushing up to grind against his groin plates. He gave a muffled moan against her mouth, which she followed by digging her fingers into the sensitive spot near the juncture of his cowl and neck. He ground his pelvis harder into hers and palmed both of her breasts, rubbing hard circles into them.

He moved downwards, making her unlatch her legs, and looked up at her with a playful glint in his eyes, then pulled her nipple into his mouth. He sucked softly at first, then harder, as she squirmed underneath him, her breath coming out in rough pants. His hands worked on unzipping her leggings, inching them down slowly as his name left her lips over and over. He lifted her up slightly and pulled the leggings completely off her body, just as she hooked her toes into the crease of his undersuit and tugged down in an attempt to pull it off. He let out a soft chuckle and took it off himself, leaving both their bodies bare.

Garrus brought himself lower, until his face was positioned between her legs. It was smooth there, save for the opening between her legs. She resisted the temptation to close them as he trailed his fingers over her thighs, and in a sudden move he grabbed hold of her ankles and spread her legs, exposing her to him. He studied her carefully, as if trying to figure out what he was supposed to do.

"It's inside," she said, making him glance up at her for a brief moment. He was unusually silent, but the thought was pushed aside as he swiped his tongue over the opening, sending shudders through her body. His mandibles tapped against her skin, clearly pleased at the reaction he got out of her.

"Hmm," he hummed, then caught her completely off guard as he plunged his tongue inside her. Her mind went completely blank at the sensation. He flicked slightly inside her, touching the bundle of nerves that almost made her shriek. Humans definitely couldn't do this. He flicked again, harder this time, making her hiss in a breath.

His mouthplates rubbed against the skin outside her opening as he fucked her with that long, amazing tongue. She could feel the muscles in her legs and pelvis tighten with each thrust, the nerve bundle inside throbbing from his insistent lapping. She moaned his name in a plea for release, her voice turning high pitched as he pressed in deeper. He responded by setting an even faster pace, which made her mind reel as black spots hovered in her vision.

She approached her high, completely unable to breathe, and with one final push he sent her over the edge. She dug her heels into the mattress as her walls clenched around his tongue, her head thrown back in sheer ecstasy. His talons gripped her ass tightly, pushing her orgasm even further. She inhaled raggedly, drawing air into her starved lungs as she came back to reality, her heart beating at a rapid rate.

Her muscles went limp as she finished, her breathing evening out. He pulled out and crawled over her, coming up to place his mouth against hers. His tongue pushed into her mouth, and she could taste herself on his tongue. "I'm not done with you yet," he murmured into her ear, pulling away and sending sparks of arousal through her body all over again. She let out a whimper as his hands trailed down her sides, his talons leaving little trails of pink behind. They stopped on her hips, and in a swift motion he turned her over onto her stomach. Her face was pressed against the pillow, but she turned her head to the side, just able to see him hovering over her. He lifted her hips off the bed with one hand, the other one teasing fingers around her wet cunt. He slid one in into her opening, and then another, stretching her experimentally and pushing them in up to the hilt. He slipped them out after a moment and pressed them against her mouth, unable to look away as she licked his fingers clean. She sucked hard on them, making him unconsciously dig his fingers into her hips and press against her. She gave them one final lick as he pulled them out of her mouth, pulling a satisfying rumble from deep within his chest.

"Tease," he said under his breath, as she felt him line up with her entrance. He entered her in one swift motion, eliciting a sharp moan from her as her muscles stretched to accommodate him. He set a slow pace at first, but she pushed back hard, coaxing him to go faster. He complied, his motions growing frenzied and rough, the ridges of his cock rubbing against the spot inside her that made her mind go numb.

She felt the familiar clench of muscles building, tightening her inner walls around him. He gripped her hips tighter and let out a groan at the sensation, head dropping back slightly as he pushed harder.

"Spirits, you're so fucking tight." He pressed her into the pillow, the roughness of it all making every nerve in her body quiver. Tension built in her body, and from the way his breathing hitched she guessed he was close too. She met each of his thrusts with her own, skin slapping against plates in a steady rhythm.

"Come for me," he murmured. The words were nearly enough to send her over the edge. His grip on her ass was getting a little painful, but it mixed with pleasure in a way that made her mind sear with white hot ecstasy. "Come for me."

And so she did. A muffled scream left her lips; her body shuddering as her vision went blank. A stream of curses left her lips as she tightened around him, her walls refusing to let his cock slip out. He gave another few thrusts to find his own release, emptying himself inside her with a grunt of satisfaction.

They collapsed in a pile of sweaty limbs and warm skin, panting heavily. He didn't move out of her, both of them just listening to the other's breathing. Eventually he wrapped his arms around her form and twisted them onto their sides, somehow managing to stay inside her still. She could feel his cock retreat slowly back into its slit, and pressed her back against his, relishing the feeling of his plates against her body.

Neither of them spoke though, as sleep threatened to grab hold of both of them. Tali remembered something fleetingly about meeting Shepard, but her mind was too tired to grasp what it was. She let her eyes close, comforted by the feeling of Garrus's body against hers, and let exhaustion take her.