1. (n) An act when a man thrusts his penis into a woman/man's anus and whispers over her shoulder, "Wow you were good, almost as good as your sister and mother." While she tries to throw you off, stay on as long as you can. Thus, you have performed the bucking buffalo.
1. I was about to do a bucking buffalo on my wife last night, but Susie came home and we had a threeway