"Hey, we're back."

Lincoln was surprised when he saw the door open. Two figures stood in said doorway - his sister Lisa, staggering, and her friend Darcy, holding her up. "Oh hey Darcy. You're back early."

"Yeah… about that…" Darcy helped move Lisa onto the couch, next to Lincoln. "She, uh…"

Lincoln sniffed, and picked up a hint of alcohol. "Lisa, have you been drinking?"

"It was only a few drinks." Lisa slurred.

"Lise, you're eighteen, you know you can't legally drink."

"It's legal somewhere in the world. Besides, if the greatest minds of two generations cannot even acknowledge my contributions to society, then why should I even care?"

"Lisa didn't get any awards in the science ball thing she went to, so she got drunk and started making a fuss." Darcy bluntly added.

"Yes, thank you for the reminder."

"You literally just- Ugh. Nevermind." Darcy sighed. "I've gotta go. Text me in the morning, Lisa."

"Sure." Lisa replied, half-interested.

"See ya, Lincoln." Darcy waved as she left, Lincoln waving back to her as she did.

He turned to Lisa. "Seriously, what were you thinking?"

"I don't know, okay?" Lisa snapped back. "I was infuriated, and I recalled the fact that alcohol is a depressant which would theoretically calm me down. It didn't." She leant her head back, a hand on her forehead. "And, as I found out, I'm a lucid drunk so I remember everything I did and that I had complete control over myself." She groaned. "So I chose to get angry. Thankfully Darcy was there to bail me out before I got too out-of-hand…"

"Thank goodness."

"But seriously, why on Earth wasn't I given even any acknowledgement? I've been a pioneer in multiple scientific and engineering fields for years. Heck, I cracked time travel, or telechronos as I've called it, but not even a participation ribbon for it!"

"That's a bit weird." Lincoln murmured. "Well, regardless," he said as he placed a hand on her thigh. "I think you've done amazing work."

"Thank you, brother." Lisa sighed. "I'm still frustrated, though, and this alcohol is doing weird things to my body and mind."

"Weird… how?" Lincoln asked.

"Blurry vision, slurring of speech, loss of inhibitions, increased libido-" She paused. "Did I say that one out loud?"

"Yeah." Lincoln confirmed. "But, if you'd like me to help you with anything-"

Lisa smirked, and spun onto her side, throwing one leg over Lincoln's and pulling herself into his lap.

"- I-I was gonna say 'anything but your libido', Lise." Lincoln looked over her sister. She was short, nearly by a head, when they were standing side-by-side, so her head was about level with his. She was a little chubby, her curves highlighted by the small green dress she was wearing, the white coat worn over it barely staying on.

"You cannot deceive me, Lincoln. I know about your exploits with our other sisters."

Lincoln went pale. "H-how did you…?"

"I have my ways." Lisa smirked. "And before your paranoia goes haywire, I'm not blackmailing you for sexual favours. I'm merely stating that we're both capable of this."

"Lis-" Before he could continue, Lisa pressed her lips to his, the strong taste of alcohol and some kind of berry hitting him. He had to admit, he kind of liked it.

Part of his mind screamed at him to stop, but like all the other times the rest of him enjoyed this, and after a moment of hesitation he deepened the kiss. Their lips parted, their tongues dancing around each other. Lisa's was typically rhythmic, and the taste of berry alcohol grew stronger. He ran his fingers through her hair, and was almost surprised when her hair managed to stay in place. Lisa cupped his head and pushed her head as close as she could to his, and her body as well.

Lisa pulled back after a few moments, panting heavily. "I can see why people enjoy this~" She discarded her coat and tossed it aside. The dress she was wearing was a high-collar sleeveless piece, cut to just above knee level and hugging her body quite nicely.

"That dress looks really good on you." Lincoln panted, running his hands along her side.

Lisa smiled. "Thank you. I would say your outfit is remarkable in its fitting too, but you're wearing your default sleepwear."

"Heh, yeah, I didn't have a fancy science party to go to."

"You didn't miss much." Lisa planted her lips back on Lincoln's, and the two continued their make-out session. Lincoln could feel his pyjama pants getting a little tight around the crotch, the buttoning on the front threatening to break or otherwise slip aside. He almost slipped out too, as Lisa bucked her hips against him and he could just feel a touch of sheer fabric on his skin. She moved again, and he felt even more fabric. His hands moved down from her sides onto her hips, and she moved again.

He suddenly felt a lack of pressure on his crotch, and Lisa twitched, moving back to look down. His member, stiff as it could be, had come loose, and was pressed up against her.

"Fascinating…" Shifting back, she placed her hand on it, her hand moving as if to study it. "Hmm… approximately sixteen centimetres long, average diameter of about four centimetres, average circumference of around eleven-"

"Lisa."

"Right, sorry. It's above average, which I'm sure you're thankful to hear." She smiled, still feeling his stiff member in her hands. She bit her lip and gave her a few test pumps, Lincoln letting out a breath he had no idea he was holding. She then let go, pulling herself off him and slipping her hands under her dress, slowly and sensually pulling her panties down from under them, a thin glistening trail following it. After discarding them, as Lincoln removed his own pants and threw them aside, Lisa returned to his lap and pressed her slit against him, the warm wet sensation welcome against his raging erection.

That niggling thought returned to the back of his mind, the one that told him to stop. As he grabbed hold of Lisa's hips and she slowly began to grind on him, the thought faded, replaced with desire and lust.

Lisa moaned, her arms wrapping behind him and pressing her body closer as her hips continued to move. The room was dead silent aside from their noises and the slight creaking of the sofa, and Lincoln was glad it was only the two of them as Lisa's moans of pleasure got louder.

Lincoln slipped one of his hands under her dress, slowly feeling her soft and smooth skin. His other hand moved up with it, lifting her dress and revealing her slightly chubby body. Lisa leant back to give him better access, removing her glasses and helping him remove her dress entirely. As Lincoln threw aside his own shirt, he looked her over, wearing nothing but a black bra that cupped her fairly sizeable breasts. "Wow, you've… uh, you've grown."

"I'm thankful I'm near-sighted, so I can mirror your sentiments." Lisa smiled, placing her glasses with her dress and continuing her slow grind.

Lincoln reached behind her and began unhooking her bra, looking deep into Lisa's azure eyes. He got her bra loose and the two of them casually threw it aside, Lincoln grabbing one of her breasts and gently massaging it.

"Nnf… Careful, Lincoln, they're a little sensitive…" Lisa stated, her grinding speeding up. Lincoln smiled, and leaned forward to place her other breast in his mouth, using his lips to gently massage it as his tongue flicked across her nipple. He pinched one of her nipples with his fingers at the same time he gently bit the one in his mouth, and Lisa bit back a loud moan, pulling herself forwards and holding him tight as he felt his nethers become even damper.

"Woah, did you just…?" Lincoln asked.

Lisa fell limp, breathing heavily. "I-I just achieved orgasm, yes…" She sighed. "I never knew I was capable of having one so… intense."

"It's more fun with two people." Lincoln smiled, stroking her hair.

"Well, allow me to repay you in similar kind." Lisa smiled, sliding down his body and onto the floor, her head now level with his member. "Hmm, it looks bigger up close. Remind me to bring a tape measure next time we do this."

"Assuming we do." Lincoln murmured to himself. "I'll try to have one hand-" He yelped, as Lisa slipped his head into his mouth and practically hilted herself, before pulling back up. "Jeez, ya could've gone slower."

"Apologies, brother. I was testing to see if my gag reflex did anything." She smirked, wiping some of her girlcum off her mouth. "Luckily it didn't."

"O-oh."

Lisa placed his glans back in her mouth and slowly bobbed her head up and down, getting a little deeper each time. Lincoln stroked her hair as she worked, and she looked up at him, smiling as well as she could.

It didn't take long for her to reach as far as she could go normally. She continued her movements, occasionally shoving him in as deep as he could go. Already excited from the grinding session earlier, Lincoln felt himself starting to get close. "L-Lisa…!"

Lisa worked double speed, then rammed her face into his crotch just as Lincoln hit his tipping point. With a grunt he gripped the couch, cumming down her warm, wet throat as his hip bucked. Lisa pulled off part-way through, a load ending up in her mouth before the rest trailed down his slick member and fell onto the sofa.

"Well, I'd call that a success." Lisa smiled, swallowing the cum in her mouth. "Not fond of the taste of your ejaculate, but it's acceptable."

"Fuh…" Lincoln barely managed to reply. "That… that felt good."

"Well, if you're ready, I would like to continue." Lisa said, moving onto the couch next to him.

"Sure thing, just let me grab some condoms from my-"

"No need for that. I'm sterile."

"Wait, what?"

"Lab accident. I have some eggs in reserve in my room, but I doubt you'd want me to use them."

"No thank you." Lincoln smiled. "But anyway, I think I'm good to go. How do you want to do this?"

Lisa smiled, falling onto her back and spreading her legs. "Like this should be sufficient for the purposes of pleasuring each other."

Lincoln felt his member spring right back up. He positioned himself so he was on top of her, and with one hand he gripped his member and pressed it against her entrance. "Ready?"

Lisa nodded. Lincoln pushed the tip in just a touch before letting go, then slowly pushing himself further in. Lisa moaned as he did, holding onto his shoulders.

Soon he found himself as deep as he could be, her inner walls holding onto him tightly. He withdrew almost fully, then slowly pushed back in, sucking air through his teeth. He built up a steady pace, picking up speed the more comfortable he got.

"Oh gosh…!" Lisa moaned, her hands moving to grip the sofa. "I-it's so deep~!"

Lincoln sped up, leaning down to plant his lips on hers. She still tasted like berry alcohol, and he was growing to enjoy the taste. One of his hands, the one least supporting him, moved to her chest and played with one of her breasts. Her moans became much louder, muffled through their kiss.

Lisa broke their contact. "L-Lincoln, I'm… ah~! I'm about to achieve orgasm again~..."

Lincoln kept his speed up, and Lisa wrapped her arms around him to pull him close as her second climax struck her with a prolonged moan. Even through it, Lincoln kept going, now feeling his begin to dawn.

Her vocalisations became incoherent and much louder, her vocabulary disintegrating into repurposed curses as he thrusted hard for a few seconds before ramming deep into her, letting out a pained grunt as he emptied his entire load into her. He went limp, falling onto her and then rolling off the couch, his still-twitching member sliding out with ease.

He finally came down from his climax high, pulling himself upright and looking over Lisa. She was panting heavily, and a thin glob of whitish fluid leaked out from her nethers.

The thought crashed back into him, at double speed. Not only had he had sex with one of his youngest sisters, she was also drunk. Anxiety welled up in him as he reached for his clothes.

"By Newton…" Lisa murmured, now pulling herself up. "That felt… great…"

"Heh, glad I could help." He grabbed her glasses and passed them to her.

She took them and put them on. "Ugh, my legs feel weak. I think I need to get some rest."

"If you'd like some help-"

"I appreciate the offer, Lincoln, but I can manage on my own." She stood up and grabbed her dispossessed clothing, and walked up the stairs. After a while Lincoln heard a loud thud. "I'm okay!"

-

The next morning, Lincoln had woken up early, hoping to clean the various stains in the living room. He was in the process of doing so when-

"Good morning, brother."

Lincoln nearly yelped. "O-oh, good morning, Lisa. Sleep well?"

Lisa, dressed in an oversized green shirt and matching track pants, yawned. "Well enough. I have one heck of a headache though, but some paracetamol or ibuprofen should be sufficient to alleviate it."

"That's gotta suck." Lincoln paused to resume cleaning, but sighed and looked back at her. "Hey, uh, do you remember what happened last n-"

"Yes."

"Oh god. Look… I'm sorry about-"

"Don't be." Lisa adjusted her glasses. "Technically I should be the one to apologise."

"But you were drunk…"

"I'm a lucid drunk. I remember it all." Lisa smiled. "It felt good, by the way. I can see why The Log has such a reputation."

She went to the kitchen, and Lincoln continued to clean. Then he paused. "Wait, I have a reputation?"