"I swear to gods, if you don't touch me right now, you'll regret it," Jim growled.
"Tsk. Not with an attitude like that. I'll touch you when I please."
Jim glared at him with slight disdain but said no more. He enjoyed being at the other's mercy though he didn't know how much he'd wanted it until it was happening. Moriarty closed his eyes and tried to calm himself. Suddenly, though, his silent pleas were answered when he felt a hot, wet mouth begin to sink around his prick. He moaned and his eyes fluttered open to glance down at the head of curls lowering itself near his groin.
"Oh, Sherlock…" James' moan of pleasure was met with a muffled hum of approval. Sherlock worked Jim with his mouth, sucking hard and hollowing out his cheeks as he bobbed his head. Again, he pulled away when Jim was close to orgasm and again Jim whined in protest, panting heavily. Sherlock squeezed Jim's cock gently, delaying his release. Sherlock moved up and caught Jim's lips in a slow, deep kiss thought Jim pulled away quickly.
"I don't fancy the way I taste, thanks."
Sherlock rolled his eyes. "Well, I /do/ like the way you taste and you're just going to have to deal with that." Jim huffed and kissed the taller man, ignoring the taste of his own cock on the cupid's bow. After a moment, Sherlock pulled away. "Come on then, on all fours for me, love."
Moriarty willingly turned onto his stomach and pushed up onto his hands and knees. Sherlock didn't hesitate to spread the arse cheeks before him and lap teasingly at the widened hole. Jim keened and bucked back against the wandering tongue. Sherlock didn't linger for long before bracing himself on his knees and spreading lube of his aching and neglected cock. He positioned himself and Jim's entrance and began to push forward slowly, rewarded with a slow, drawn-out moan from his lover. Sherlock grasped Moriarty's hips as he bottomed out, buried to the hilt.
"So tight," Sherlock groaned. "So good." He drew a deep breath and pulled out almost all the way before pushing back in. Gradually, he found his rhythm and he mind never felt so clear. Being used to being the one on the bottom, Sherlock found that topping was just as good and was reminded that sex was just as good as- perhaps even better than- the drugs he had wasted years of his life on. He relished the feeling of Jim around his cock, moving quickly and deeply and pulling Jim's hips back onto each of his thrusts. The room was filled with the sounds of Moriarty's mewls of pleasure and skin-against-skin. Sherlock panted as he moved faster, moving one arm from James' hip to wrap around his stomach. The other hand moved to stroke Jim's cock and each snap of the detective's hips drove Jim's cock into his fist. Jim did his best to rock back into each thrust, adding to the friction. He gripped tightly to the bedsheets, mewling and moaning and panting. He wouldn't last much longer.
Sweat made Sherlock's curls cling to his forehead and the back of his neck as he moved, panting and grunting slightly. He watched Jim writhe and buck and admired the way his back glistened with sweat. Together they moved until Sherlock keened.
"Cum with me, James," he breathed, slowing his thrusts to focus on depth and power. He thrust deep and rough until he stilled, releasing rope after rope of thick, hot cum. Jim moaned wantonly as he was filled and spent into Sherlock's hands and over his bedsheets, leaving a bit of a puddle. Sherlock released his member and obscenely licked every bit of the criminal's spunk from his hand.
"Sherlock," James whimpered, and the detective slipped his softening prick from the other's body. Moriarty turned and collapsed onto the bed on his back. "Christ."
"No, I think just 'Sherlock' will do," he teased. Jim chuckled and shook his head at that. Sherlock curled up next to him with his head on Jim's chest, listening to his loudly thumping heart with a small smile on his lips.
"Hmm… I owe you a fall, Sherlock," Jim hummed.
"I believe I have already fallen."
"I don't mean from a building. Besides that wasn't actually you. I mean falling… in love."
"I knew what you meant. My answer still stands." Sherlock looked up at him then and Moriarty smiled widely.
"You really meant that?"
"Of course. There's no other explanation for the way you make me feel, James."
Moriarty pulled him into a deep, passionate kiss and held it until neither of them could breathe. "Then run away from all of this with me. You're supposed to be dead anyway. We can start a new life together. Anywhere you want."
Sherlock thought it over briefly. "Paris?" Jim didn't respond to that verbally. Instead he smiled and pulled Sherlock into another kiss, wondering vaguely why they had waited so long and lied to themselves daily.