He only meant to complain; you didn't take serving girls on hunting trips, and the alternative interpretation didn't even occur to him until Merlin said indignantly, "I'm not going to do that!"

Yet another beauty st_xi_kink is responsible for. The prompt is: Kirk turned tricks when he was younger, so when it becomes apparent that some seducing is needed, he volunteers. Spock is uneasy in the beginning and tries to reason with Kirk. And we all know how that goes.