Sherlock leaned into John, biting his ear and tugging at it just on the cusp of too hard.

"Come for me.." He growled, a command in a deep, rumbling voice. "I want to see you come undone." To accentuate the point, his stroking got faster, up and down John's cock. He rubbed his thumb against the sensitive glans on every upstroke, and gave the base a little twist on the down stroke.

"NOW..." He commanded. He was right at the edge but trying to hold back, waiting to feel John just shatter under him.