The act of insulting a woman while you're fucking her, just as you're about to cum. She will try to buck you off and the resulting ride will make you cum even harder.
I was buttfucking Sally last night, and just before I was about to cum I told her that her sister was a much better fuck. Man that turned her into a raging angry donkey and it made me cum even harder as she tried to buck me off. I felt like a rodeo star!