Oh wow! That was super hot and sexy! :P So far I've read only a couple of Star Trek fics of the Kirk/Spock variety that also work on some level but I don't have a fixed OTP yet, so it's fun to play the field. :D McCoy pining for Kirk in a very manly way and Kirk taking matter into his own hands (pun intended) was so much fun to read. And McCoy being the heart-shaped peg was just ♥.

(His hand is trapped between their bodies and Jim's hand, warm and naked, feels different from his own, clothed and chilled. Not body?)