Really, Matt could've figured this out before: There's no way the marks he's left are gonna bruise like the ones that were already all over him.

Still, that's the purpose of lots and lots of field trials. He turns his head and bites Sherlock's neck, lingering over it; he doesn't plan to break skin, but he lets his teeth dig in harder as he goes.

He presumes he'll be told to stop if he goes too far.