John opened the fridge, "Sherlock, I told you to get the damn milk weeks ago!"

"I did, but we used it, remember?"

"Yes," John cringes at the memory of the milky bath he was forced to take under Sherlock's watch.

"I got lots of scientific data from that experiment," asserted Sherlock, mentally revising the growing list of ways to give John a boner.

The list, so far having 11 items, currently contained things such as: Pawing at John's arse, pawing at his own arse, watching him bathe, etc etc etc.

"So, when are you going to request my assistance in another 'experiment' of yours, Sherlock?" John teased.

Sherlock could already feel the blood rushing to a certain member of his own body as he devised his devious plan.

"Well, I am quite curious to learn more about how different types of pant fabric effects the sensitivity of nerves in the pelvic region"

And for his own participation: how different colours affected the release of the serotonin and oxytocin release that cause physical and emotional attraction to another being.

"So you want me to get my red pants?" asked John, a knowing smile on his face.

"And my ones, with the bees on them," Sherlock replies excitedly, already shivering with anticipation.

John ran to his bedroom, the one that they used most often, to find the box labelled 'experiments for two', while Sherlock locked the door to ensure that Mrs Hudson didn't interrupt the gathering of data.

Sherlock calls John as he slides on the bright yellow and black cotton of his pants, "You know, colours get richer in water and seeing as we've already tested this before…" he trails off.

"I'll pop on the bath," said John, before adding "perhaps you could grab your sheet, Sherlock? I do think that the colour white might provide some interesting results."

Of course, the infamous sheet incident of 2011, Sherlock pondered, THAT was an interesting developments in their relationship.

Sherlock found the sheet at the foot of their bed, a smell lingering on it from their previous session, when another smell wafted through the apartment. Mmm, bubble bath.

Sherlock almost sprinted to the bathroom and when he arrived he found John sitting seductively on the edge of the bathtub, legs splayed open.

"I owe you a fall," he said, before gently pushing John backwards into the steaming bubbles.

Sherlock gazed into the deepening redness of John's bulging crotch.

"Sherlock, don't joke about that. You know that your 'death' nearly killed me, I don't want to be reminded of losing you when I'm trying to… you know… get off with you."

Sherlock chuckled throatily as he placed both hands on John's kneecaps, staring into his gleaming face.

"Well, I'd better keep your mind off it then. Would you rather concentrate on something more pressing?" he asked, taking John's hand and moving it to the mound covered by the bee pants.

His hand quivered on the cotton covered bulge, urging it to grow harder and longer.

"Here's my conclusion from this experiment. This fabric is… quite… restricting," panted John, longing for closer contact.

Sherlock stayed at a tantalising distance from John, forcing him to make the first move; to pull Sherlock down on him.

John grabbed a handful of Sherlock's silky hair, pulling his face down so that their lips could meet. "Pants… off…" he demanded as he gasped for air between contact.

Sherlock stood in the bath over John, rhythmically swaying as he slipped the already transparent bee pants to his knees revealing his engorged member.

He then bent down to John, patting the bulge through the red pants before walking his fingers to the waistband, pulling it off in one go.

John reached up, exposed and horny, to wrap his hand around Sherlock's member.

Sherlock closed his eyes and moved his pelvis forwards, as John sat on his knees and kissed the quivering hardness.

In one gulp he took the entire length into his mouth.

Sherlock placed his hands on John's shoulders for stability as he swayed back and forth with his eyes closed, his rhythmic movements getting faster as John's tongue worked it's magic.

John's tongue flicked around head in one smooth movement and Sherlock couldn't take it anymore, he pushed John backward and held off his orgasm.

Sherlock turned around and John grabbed his waist, guiding him down so that his opening slid perfectly around John's point, as it had done so many times before.

Sherlock slid up and down with ease, using the bubbles as lubricant, until he found his rhythm and began to pick up pace.

"Ugh," said John, as he got closer to lift off. "I need you to come with me," he said, reaching around Sherlock's torso so that they could come together.

His thick fingers wrapped around Sherlock's penis, moving up and down and tickling the head. Pure bliss.

Downstairs, Mrs Hudson looked up from her crossword as she heard shouts coming from the bathroom in 221B. "Boys," she muttered, smiling knowingly, before putting on a record to give them some privacy.

Sherlock screamed an unbelievably sexy scream as he came, sending white hot liquid over his chest.

Mrs Hudson realised that her record player couldn't be turned up any louder, so she scribbled a note that she was getting some groceries, before grabbing her coat and walking outside.

"Sherlock, we have a problem! I FORGOT TO WEAR A CONDOM!"

"Don't worry, I won't get pregnant."