Watson gasped a little, though the pain that came of the pressure there was a double-edged thing, serving to sharpen his pleasure that much more. He was in that heightened state where almost nothing could have taken away from the situation, not to any degree.

He could have lost himself in the perfection indefinitely, his cock in Holmes's mouth, the only slightly frantic pace of his thrusts. He could, however, feel his orgasm building, and the urge to move a little more desperately.

"Sherlock," he gasped, half an endearment, half a warning. Words beyond that were beyond him. "Sherlock--" His orgasm hit him, almost before he'd got both syllables out, and his fingers clenched again in Holmes's hair.