AN: Written because Jim won't GTFO of my head, and I wasn't letting him at Caring is a Mistake again, and this idea kept interrupting me in class. Also, need to get myself warmed up for writing smut if I ever plan on writing Unplanned.

Mostly though, I just didn't want to take my philosophy final.

Moriarty circles around the doctor, the innocuous, inconsequential little man that has somehow captured the attention of Sherlock Holmes, his greatest rival. The only vaguely interesting person on the planet. But just because he isn't interesting doesn't mean he won't suit his purposes. Jim needs to send a message, needs to make things explicitly clear to Sherlock. Back Off.

Whipping is not enough to send that message. But it is certainly a start.

Moriarty tightens his grip on the belt in his hands, anticipation coursing through him. He doesn't usually get his hands dirty, but for Sherlock's pet he will make an exception. Dr. Watson's wrists are bound, attached to a bar in the wall about two feet above the man's head. He has been gagged and stripped of his shirt, facing the wall.

The belt makes a delicious crack as it connects with the pale, scarred skin, and Doctor Watson grunts, the sound muffled by the gag. Moriarty raises the belt again and again, almost without conscious thought and the cries the doctor is making get louder and louder. By the time Moriarty returns to his senses, the Doctor's back is covered in raised red welts and blood.

Moriarty remembers now why he doesn't get his hands dirty. Hurting people, making them bleed, watching them suffer, it does things to him. As far as Moriarty is considered, his body is not to do anything without his permission. He certainly didn't give it permission to do that, he thinks as he stares with distaste at the bulge in his trousers – they are far too well fitted to allow for tenting, but that only makes the situation even more uncomfortable.

Other men might take advantage of the bound, helpless, undeniably attractive man in front of them. Moriarty is not other men. Rape is too pedestrian, too dull. All his partners have been more or less willing, and he is going to keep it that way.

Moriarty decides he's just going to ignore it. Sending Sherlock the message is more important than ensuring every bodily need is completely neglected. Perhaps not the belt this time, another instrument might not produce the same effect.

Moriarty was considering his options in that area when he became aware that the sounds the doctor was still making had a distinct pattern. A phrase, repeated over and over. He creeps closer to John, listening. Unable to allow himself certainty in his conclusions without more data, he removes the gag.

"Don't stop…"

Then there is the fact that the doctor's pants are far looser than Jim's own and quite perfect for tenting, if the current information is anything to go on.

Everything clicks. Jim, as much as he tries to deny it, is a sadist. John is a masochist (which sheds all sorts of light on his associations with the consulting detective). Despite what that would imply to most, the army doctor is not at all submissive – he is a drill sergeant. And Jim? It is far from uncommon for people with strong personalities to take the non-dominant role in the bedroom.

Several hours, a knife, three orgasms and a ruined Westwood suite later, Jim and John lay on the floor, chests heaving staring at the ceiling.

"Sherlock is going to kill me when I get home," the not-at-all inconsequential man next to Jim says, seemingly resigned.

"My dear Johnny," Jim says, dragging his fingernails down John's chest with enough force to leave angry red lines, "you're assuming I'll let him have you back."

AN: Love? Hate? Smut needs a restraining order against me? Let me know!