A/N: I haven't written a fic in years! After recently getting into Sherlock and reading some other nice stories I was inspired to write something again. This is my first attempt at JohnLock, hope you enjoy.
John stepped into the steaming shower and emitted a sigh of relief as the hot water flowed over his aching body. He could feel the dirt and stench of what was an excruciatingly long three-day excursion through the sewers of London washing away. They had been contacted by Lestrade after he received post from a killer confessing his crimes and leaving clues to where he had slain his victims. John laughed remembering how frustrated Sherlock had been after being handed a fistful of riddles. Sherlock hates riddles.
John reached for a bar of soap and began to wash up, mind still fixed on Sherlock. "God is he extraordinary" thought John "his intellect, demeanor, those lips, that hair, and Gods that voice!" John imagined the low, velvety growl of the detective's voice whispering his name "John." John absent-mindedly rubbed the soap over his chest and abdomen while imagining Sherlock stripping down after the long day; his firm chest and tight ass. John felt himself grow hard at the thought. His right hand found its way down to his erection as he imagined Sherlock welcoming him into his mouth, his soft wet lips sliding down his shaft. John began to stroke himself at the image of his friend taking him in and out of his mouth, deep into his throat, sucking, licking his tip.
John was panting as he stroked faster and faster. He could tell he was going to climax soon. He imagined grabbing those beautiful curly locks on the detective's head and forcing him to take it deeper. As John imagined himself climaxing into Sherlock's mouth, a sticky sheen on his lips, he came spilling his seed onto his stomach. The bar of soap he didn't realize he'd been crushing fell to the shower floor with a bang and John let out a guttural moan of pleasure.
John was snapped out of his moment of ecstasy by a loud rapping on the door followed by "John are you alright?" Sherlock had heard him. John cursed himself for being so loud.
"Uh yeah, yeah I'm alright. No…um…no worries mate." He replied thoroughly embarrassed. Sherlock had asked if he was alright so maybe he hadn't betrayed himself as he feared.
John finished washing himself off and stepped out of the shower to towel dry. He figured he could make up some excuse if Sherlock asked what had happened.
Sherlock was walking through the hallway toward his bedroom when he heard John yell in the bathroom. He instinctively knocked on the door and asked if his friend was alright, but as John called back to him, memories of similar occasions came flooding into Sherlock's mind. He remembered twice walking past John's bedroom and hearing that yell; no not a yell, a moan.
Sherlock stopped, trying to conceive what could make John moan like that when it clicked. John was pleasuring himself. Sherlock felt his trousers get uncomfortably tight at the thought. He ran into his bedroom struggling with the zipper on his pants as he went.