It's possible Sherlock may feel no shame. At all. Ever.
John's still not absolutely sure about this, which is why the good doctor enjoys testing his lover's limits—well, his sexual limits—seeing exactly how far he's willing to go. And though he suspects he should feel guilty about it, the boundary John most enjoys seeing Sherlock push up against is sex with inanimate objects.
Well not, you know, inanimate objects like spatulas or cucumbers or anything weird. And not sex really, just more a series of delicious masturbatory episodes, if you must put a label on it. In the last couple months, for example, there's been four especially interesting times John has dared Sherlock to—let's get euphemistic—"make love" in front of him to:
One of John's Jumpers
The first time it happened (there have been other instances by now) it was kind of sweet, almost tender.
It basically started one rainy morning in the sitting room, with a languid Sherlock stretched out on the sofa, plucking the strings of the violin, now and again murmuring suggestive things in a bid to distract his blogging doctor a few metres away.
John tuned out most of the interruption until Sherlock said something particularly wicked. Though he continued typing, a smile did ghost over his face and that was all Sherlock needed to amp up his seductive little monologue, trying to turn the doctor on, getting himself hot-and-bothered instead.
John let him ramble another five or ten minutes, fully aware of what Sherlock was doing to himself. Then, as he finished up his post, he had a small moment of…inspiration. Knowing Sherlock's odd penchant for his jumpers, John stripped off the one he was wearing, tossed it to his sweetheart and said, "Here you go, the ghost of John. Have at it."
When Sherlock sat up and started to tug the warm blue wool over his head, John said carefully, "No. No. Have at it."
Sherlock looked at John and then slowly smiled a beautifully innocent smile, a child-like smile, a smile not even a little bit perverse. He laid back down, the jumper clutched in his hands. Then, holding his lover's gaze, Sherlock opened his mouth, tucked in the tip of one sleeve—on which he proceeded to bite—and then with both hands he slowly slid the rest of the jumper down, down, down between his now spread thighs.
And proceeded, of course, to thrust against it. In absolute silence. Still never looking away from John. For his part John wasn't sure where he wanted to look more: at Sherlock's bared teeth biting, at Sherlock's long neck arching, at the hands between his legs pressing, or at those slender hips rolling up and into a cozy knitted bundle that John may or may not have been slightly envious of.
In the end John simply took in the whole gestalt for as long as it lasted, and because this was Sherlock we're talking about, it lasted. Well of course it did, because Sherlock not only didn't look away from his lover, he barely seemed to blink, so intent was he on watching John—"I'm not really in the mood, love"—get in the mood.
Only once he was sure he had every bit of John's attention, mentally and physically, did Sherlock slide in the one absolute, guaranteed sexual fail-safe when it came to the good doctor: Sound. But just one. A tiny desperate growl from the back of the throat.
When John dragged his tongue across his lower lip and slid his hand into his pajama bottoms, Sherlock thrust his hips up into that soft, cuddly, innocent jumper a few times more, and shook through his orgasm in absolute silence.
John? John was almost as quiet.
He was utterly silent as he watched Sherlock come. He said nothing as he watched Sherlock come back down to earth. He made not one peep when Sherlock slid off the sofa and crawled toward him. And the sound he made as Sherlock, on hands and knees, disappeared beneath the table? Very small.
When Sherlock tugged John's pajama bottoms down and took his cock in his mouth and started sucking, however, all bets were off. And speaking of off, the sounds John made as Sherlock got him there, well quiet is really the exact opposite of what they were.
The story is called "Four Shame" for a reason. There'll be four examples of times Sherlock (or is it John?) showed no shame. The next one may or may not involve the skull. Just sayin'.