A/N: Several warnings for this chapter include: Johnlock smut, OctoJohn, PWP. Please do not read if any of this bothers you! (Next chapter should be much more your style if this one grosses you out, I promise you!)

Day #10: Octoboy

Curiosity

(Rated M)

Sherlock had known that John was an Octopi about three weeks into their flat share. John, of course, didn't want Sherlock to know; that much was obvious. To the general public, being an Octopi was a shameful thing; the eight tentacles in place of two legs was considered an undesirable thing. Sherlock found them fascinating, but he had never been given the opportunity to study them as the Octopi didn't trust humans, and vice versa. Naturally, he was excited when he discovered that John's slight limp was an indicator that he was attempting to use the tentacles as makeshift legs, always hiding behind long, baggy trousers. He had yet to figure out how to approach the subject with John. Scaring away the doctor was not something he wanted to do. John was his only and best friend, and the idea of 221B empty of him was a lonely thought.

They had been living together for over two years now, and there was a familiarity with their routines, hectic as they were. John had Thursdays off from the clinic, and Sherlock usually spent his Thursdays in Bart's, using the lab equipment to perform experiments that John wouldn't allow in the flat. Molly's lack of any decent cadavers on that particular Thursday had a petulant Sherlock at home several hours earlier than normal.

Sherlock had flopped down in his usual spot on the sofa when he heard a soft splashing sound coming from the bathroom. Sherlock sat up immediately, his eyes alight with curiosity and anticipation. John believed Sherlock to be out of the flat, and he was currently taking a bath, which would indicate that he had his tentacles free. He had heard rumours of what the Octopi tentacles looked like, anywhere from drab grey to neon colours, but he had never seen them for himself. John, of course, didn't have to know that he had peeked. John didn't even know that he knew about him.

Sherlock padded down the hallway, his stocking feet making only the barest whisper of noises. He wrapped his fingers around the door handle as soon as he reached the door, carefully turning it. Unlocked. Sherlock smirked to himself, pushing the door open until he could peek in.

The bath was to the right of the door, pressed up against the wall and allowing the bather either the visual of the door or the window. Thankfully, John had chosen the latter, facing away from him. He was slumped down in the bath, muscles relaxed as steam rose from the bathwater. His eyes moved from the wet hair of his flatmate, sweeping across his broad, muscled chest, over the water that hid his pelvis, until he saw them.

A few of John's tentacles were hidden in the water, soaking up the abundant hydration, but a few were draped over the sides of the bathtub, one curling back and forth in a manner that reminded Sherlock of a cat's tail.

The tentacles matched the colour of John's eyes, a deep dark blue that instantly reminded Sherlock of safety. Where Sherlock stood, he could see that the colour grew lighter on the bottom side of the appendages, shifting to a light blue. He was surprised to see that the tentacles lacked suckers, but were entirely smooth.

Sherlock was so lost in his observations that he didn't noticed that he had moved into the bathroom completely. It wasn't until he heard a sharp gasp and saw the swift disappearance of the tentacles that he realised he had been found out.

"Sherlock!" John cried, causing the Consulting Detective to look at his face. Shock was the most prevalent emotion, but he could sense the anger and horror simmering below the surface. "You can't just…I mean, this was my private time and I-"

"You're worried about my reaction to your tentacles." Sherlock stated with a roll of his eyes, "You shouldn't be. I've known since you've moved in."

John gaped at him for a few seconds, his mouth hanging open. "You've known that long, and you didn't tell me?"

"You would have had an adverse reaction, much like now." Sherlock sighed. "I feared you would leave if you knew that I was aware you were Octopi. Your tentacles are quite…fascinating."

"Fascinating?" John rolled his eyes, one of his blue tentacles snaking out of the water. "They're….they're awful!"

"No they're not." Sherlock insisted, reaching a hand forward to stroke the appendage. John shuddered at the touch, his eyes falling closed at the contact. Though it hadn't been the outcome Sherlock had been expecting, it was certainly delightful.

"Sherlock…ah…" John tried to speak, his voice coming out rougher than normal. "You probably shouldn't…"

"Erogenous zone?" Sherlock asked, his fingers tracing light circles on the blue skin. It was surprisingly soft and silky, slicker than normal skin, but not disgustingly so.

"Ah-yeah" John replied, beginning to pull the tentacle away, jumping when Sherlock reached out and wrapped a hand around it, keeping it near. "What are you doing?"

Sherlock hummed by way of response, bringing the tentacle in for closer inspection. Flashing John a quick smirk, he licked a quick strip up the appendage, ripping a groan from John's throat.

"If you are uncomfortable, please let me know." Sherlock said, his hands slowly sliding down the tentacle. "If you want to stop-"

"Oh god, don't stop." John breathed, another tentacle appearing, snaking around Sherlock's waist, pulling him closer. "Don't stop."

He obliged, continuing his ministrations to the first tentacle, a second and third quickly pushing off his coat, nimbly unbuttoning his dress shirt and trousers. Sherlock used his free hand to push his pants down, his cock bobbing free. John guided him towards the bathtub, tentacles dancing over his skin as he stepped into the warm water. They glided along his back and stomach, smoothing across his chest, and more agreeably, his arse.

Sherlock used his other hand to stroke a tentacle that was wrapping around his left leg, the one he had been lavishing with attention earlier securing his right, keeping his legs spread. The tentacles that had be on his arse now spread him open, allowing yet another to circle teasingly around his hole.

"Oh god, John." Sherlock gasped, attempting to squirm towards the light pressure. John chuckled softly, and Sherlock grabbed him by the shoulders, pulling him into a bruising kiss. The blond gasped against his lips, free tentacles wrapping around his torso.

"John." More pleading than anything else. Sherlock more felt than heard John's resulting moan, lips continuing to move against each other sloppily. Sherlock felt a sweep of John's tongue demanding entrance, and as soon as he opened his mouth, he felt the tentacle circling his hole begin to press in gently, causing Sherlock to arch his back, pulling John's upper body with him.

"Sherlock." John responded breathily, and Sherlock could feel the tentacle writhing inside him, stroking against his prostate in a way that made it impossible to hold back a whimper. "Sherlock, I need you inside me."

Before Sherlock could even begin to wonder how that could be possible, John had shifted himself around, tentacles squirming pleasantly as he lifted his arse up, revealing to Sherlock that he was very much human in the arse area. Sherlock spread John open, surprised to discover that he was already well prepared. He looked up at John curiously, met with a smirk that reminded him of himself.

"These tentacles have to be good for something, right?" John said nonchalantly, the tentacle inside Sherlock swiping across his prostate quickly, sending a shot of pleasure dancing up his spine.

"God, you're amazing." Sherlock said, pressing a kiss to John's spine before lining up with his hole, sliding in to the wet heat. John groaned, the tentacles not currently in use began wrapping around Sherlock, smoothing over his chest, back, and neck. They felt like a thousand tongues, licking in all the perfect spots in tandem. The sudden influx in pleasure caused Sherlock to buck, pulling identical moans from both of their lips.

"Sherlock." John's voice was low and rough, a sound that went straight to Sherlock's cock. "God, please fuck me."

He didn't need to be asked twice. Wrapping his arms around John, he began to move his hips, shuddering when he discovered that not only was he fucking John, but fucking himself on him as well. The pressure from both ends was almost too much, and he knew he wasn't going to last long.

One glance at John showed that he was experiencing a similar struggle, his skin flushed and ecstasy clear on his face. Sherlock watched as John opened his eyes, looking immediately at his face. Their gazes locked, and it was suddenly too much for Sherlock, the heat that had been building in his abdomen boiling over until he was filled with a white-hot bliss, spreading to the tips of his fingers and toes. He was distantly aware of John coming not too long afterword, his name on the other's lips.

When the haze cleared, Sherlock discovered he was lying on John's chest, the other having relaxed back into the tub once again. All eight tentacles were wrapped around him now, making him feel safe and secure. Sherlock looked up at John, a small smirk on his face.

"I am still curious about your species." Sherlock teased, drawing out a chuckle from the blond.

"I'll tell you whatever you want to know later." John replied. "But first, we need to get clean."