Jim was together enough to figure that out. His sharp spike of alarm was warning enough for Spock, and he caught Jim when he shoved up, feeling his own clothing rough against Kirk's back and buttocks through telepathy, counterpoint to his own hands hot against Jim's cool chest and stomach, and while lust momentarily surged within Jim at the feel of Spock's erection digging into his ass and Spock's hands on him, he managed to keep focus. "The fuck?