A/N: this is my first time writing smut, so... yeah... Anyways, I've just always loved this pairing and I hope you enjoy it.

Disclaimer: Don't own a shit. It all belongs to Cassie Clare.

Warning: cross-dressing, smut, Jimon, boyxboy, love, 3

Note: This is based off of a scene in The City of Bones, but I actually placed it in between CoB and CoA, so keep in mind that Clary and Jace are siblings. After the battle with the Greater Demon. I really loved the conversation between Clary, Jace, and Simon. So, I had to do something right? Anyways, here's the conversation.

"Do you remember back at the hotel when you promised if we lived, you'd get dressed up in a nurses outfit and give me a sponge bath?" asked Jace.

"It was Simon who promised to give you the sponge bath."

"As soon as I'm back on my feet, handsome." said Simon.

"I knew we should have left you a rat."

The door to Jace's room opened slowly and in snuck his lover. Simon knew that the blonde was probably asleep, but he didn't care. He came here to do something and he was going to do it. The brunette admitted he was a little nervous, but just because that they had never done something like this before.

The brunette chewed on his lip as he gradually crossed over to the other one's bed. But, instead, the mundane turned around to head back to the door. He was beginning to debate if this was a good idea or not. Taking a step forward, he hesitated to leave. He was already dressed up…

Simon turned back around and took a look at his lover. Jace was asleep on his bed, like the brunette had guessed, and had one arm above his head, draped across the pillow. Biting his lip, Simon pushed his glasses up and studied his boyfriend. His hair framed his face in a way that made the mundane want to run over and make out with him. A slightly brighter blush came onto Simon's face, considering he already had one on his face because he thought his outfit was ridiculous.

"Stop pacing, mundane… I'm trying to sleep." The tired mumble came from the Shadowhunter laying on the bed and caused Simon to jump and turn a bright shade of red. He was just glad that Jace hadn't opened his eyes yet.

Simon was determined to keep quiet, otherwise he would have made a snippy comment. He struggled to keep balance as he walked over to the bed (you know, because he was wearing heels), studying the other's face. Slowly, he straddled the elder's waist and his legs slid on either side of him. The brunette lowered himself onto his elbows, which were resting on Jace's chest and his hands rested right next to the blonde's neck. The golden eyes snapped open to look up into dark brown eyes through the glasses that rested on the bridge of the shorter one's nose.

"Well, isn't this a nice way to wake up?" Jace practically purred in soft and seductive tone, moving his face up to get a better look at Simon. He scanned the younger quickly and raised an eyebrow. "Are you wearing what I think you're wearing?"

The brunette's eyes went wide, a vibrant shade of red rising quickly to his face (and it had just went away too!) and he opened his mouth to say something, but then closed it. He didn't know how to answer that. Simon was fairly new to all of this stuff, but he figured, well, that Jace would like it.

"Uh… I, um, yes?" A sly grin rose to the blonde's face and his hands moved to slide down the skintight dress covering Simon's body. The brunette shifted his weight forward so he was leaning on his lover completely, a shudder rolling down his spine and soft gasp elicited from his lips.

Jace's warm hands slithered down to grope his nurse's ass, causing the boy above him to inhale sharply. "Doesn't my little nurse have a job to do?"

Simon felt his throat tighten slightly at the Shadowhunter's tone and his hands moved to cup the face in-between his wrists. The mundane's hands were gentle in grabbing his 'patient's' cheeks. "I believe I do." came out in seductive tone that Simon didn't even know he had before kissing his lover passionately.

Pressing even closer to Jace, Simon pried at his boyfriend's mouth with his tongue and was granted access with a low groan. His tongue delved into the blonde's mouth as they fought for dominance. It was a fight that Jace always won, but the continued the tradition anyways.

The brunette's hands slid up into the silky blonde locks of his seventeen year old lover and pulled the his head back, deepening the kiss. A few moments later, Simon pulled away and both of them panted for breath, their breath mingling.

A firm squeeze on his upper thighs let the cross-dressed boy know to keep going. Simon was feeling better about this now and set his hand on top of the blonde's forehead. A smirk came onto his face and he moved his face closer to the young adult's under his. Mustering up the most stable voice he could, the brunette spoke. "Looks like we have a little bit of a problem. You've got a slight fever."

He pulled his glasses off and set them on the nightstand, his chocolate brown eyes fogged over with lust. "But," he purred lowly in Jace's ear. "I bet I can make it go higher."

"I don't doubt that." the Morgenstern boy's voice came out in a husky tone, clearly showing he wanted more. Small hands moved down to his pale sleep shirt and slid it right off of his body. Simon stretched his body out on top of Jace's and he bent his knees so his feet were in the air. He leaned backwards and grabbed the bright pink high heels on his feet and chucked them across the room.

"Hate those damn things." the nurse muttered and leaned back down to brush his mouth across Jace's neck. He gently sucked on the blonde's neck, before nipping it and was sure to leave a dark purple mark. "No healing runes, mister. I get stuck with a hickey, so do you."

Jace chuckled. "Who said I was going to give you one?" The brunette just glared at him before silencing him by tracing all of Jace's old faded runes with his tongue. The blonde groaned when his lover's warm tongue traced his chest and stopped on his nipple, tugging it into his mouth and pulling on it with his teeth.

Simon's hands glided down his lover's torso and to his waistband. He tugged on it playfully and his hand swept over to the center of his legs, leaving the shorts on. The brunette made his way down to Jace's waistline and pulled at the blue shorts with his teeth. He knew it drove his boyfriend crazy when he did that, and that's exactly why he did it.

The sixteen year old gradually pulled the article of clothing of with his teeth, being sure to brush over his sensitive spot as slowly as possible. The blonde under him let his head fall backwards and moaned, urging his lover to hurry along. Simon stripped him off the rest of his clothing before stroking his half-hard to cock quickly.

Jace panted softly at the feelings and suddenly wanted Simon nude as well. He worked at the buttons on the nurse's dress and slipped it off of the shorter one, with very little difficulty and wasn't surprised to find that he wasn't wearing underwear. The little headpiece that was resting on his lover's mop of brown hair was soon discarded as well.

The brunette lowered his mouth onto Jace's aching cock, licking the underside carefully. The movement of his head was unhurried and loving as fingers tangled in his dark hair. Strong hands tugged at his hair and urged him to bob faster. Simon obliged, doing so quickly and taking the large cock deep into his throat.

"Gods, Simon." Jace hissed through his clenched teeth as a pool of warmth built in his stomach and propped himself up slightly against the pillows, pulling Simon up the slightest bit. The brunette looked up and locked eyes with the other boy. It was such a turn on…

Simon could feel when his lover was about to climax by the hands tightening in his hair and he pulled off before the older boy could, causing him to groan in disappointment. The brunette moved up to kiss the Morgenstern teen with a passion before pulling away to make the older boy watch him finger himself.

The mundane put his fingers in his mouth, sucking on them with half-lidded eyes and swirling his tongue around them. He purposely made a show of it for the older boy and slowly slid them out from between his lips and down to his entrance. Positioning himself on his knees, Simon let his head fall forward onto Jace's shoulder, moaning loudly as he fingered himself. "Jace… Nngg… Gods, Jace…"

Suddenly, his hand was pulled away from his hole and the blonde's slim long pointer finger slid in. "That's my job." Jace hissed possessively in the brunette's ear as he writhed over him in pleasure and penetrated the boy with a second finger. The Shadowhunter sucked on the lobe of Simon's ear as he worked his fingers, enjoying the moans and mewls that came from the mundane's lips.

"Jace, Jace… Oh, Gods, Jace, right there!" Simon's hands had somehow gotten to the taller one's shoulders and was clawing at them desperately. The blonde slowed his fingers down and purposely curled them against the small boy's prostate causing him to whimper in need and pleasure.

"You mean like this?" the teen copied the action, causing the smaller to cry out in bliss. Inserting a third finger, he stretched the younger teen's hole. "Damn, Simon, no matter how many times we fuck, you're always as tight as a sweet little virgin."

"Nng! Please, pl-please, Jace! I need you." The brunette begged and in one swift motion, the seventeen year old slipped his fingers out and moved Simon into his lap, resting right above his hard on.

"Show me how much you need me." Jace's fingers slid down the slim body of the sixteen year old and landed on his hips. The brunette let out a soft whimper and balanced himself using the Shadowhunter's shoulders. He lowered himself onto the elder boy and cried out at the sweet and familiar sensation.

"Jace…" Simon whimpered quietly, squeezing his hands down on Jace's shoulders tightly as the older boy waited for him to adjust. When he was ready, the brunette slowly used his legs knees to pushed himself up and down on the Morgenstern boy's lap.

The mundane mewled in bliss and the blonde leaned forward to suck on his neck, gently helping Simon on his mission for release. He helped his lover bounce on his lap, causing both of them to moan in pleasure.

Simon released a loud moan with a cry of Jace's name and cupped his face, pulling the older teen into kiss him desperately. They continued their love-making session in one of the best ways, passionately. As the brunette slammed down, he felt the familiar warmth in his stomach and cried out as his toes began to curl. "Nng… I'm so, so, close, J-Jace!"

"Simon," the Shadowhunter grunted against his neck and his hand went down to grab Simon's leaking cock, stroking it in the same rhythm that they were going to. Tears of bliss leaked out of the brunette's eyes as he cried out in bliss, hitting his peak. Soon after, Jace climaxed as well, riding out his orgasm.

After a few moments, Jace rolled them so they were laying on their sides and kissed the smaller boy slowly with an unspoken love that they both felt. Simon's arms went around his neck loosely and he pulled himself closer, releasing a quiet gasp as the blonde's cock slid out of him.

Soon enough, the brunette was hard again from their second make out session and whimpered when his lover pulled away. Jace slid off the edge of the bed, glancing at the clock. It was almost six a.m. He should probably go check on Clary, they really needed to talk. The Shadowhunter stood, stretching and his runes shimmered in the dull light coming in from the window. He grabbed a pair of skinny jeans and pulled them on.

"Jace…" Simon whimpered softly, pleading with the blonde to get him to stay in bed and watched him pull on a black short-sleeve shirt. His lover looked at him with a grin.

Jace leaned over and pecked his lips. "Why don't you put on a shirt or something? But, don't you dare touch yourself." he warned, narrowing his gold eyes. "You have to wait until I get back."

"Jace…" The brunette tried to plead once again, but to no avail. He watched his Shadowhunter walked out the bedroom door. It slammed shut behind him.

Damn it, Jace was such a fucking tease.