Upon the act of coitus of the "doggy" variety, the male partner (cowboy) grabs the hair (mane) of the female partner. In this instance the female partner will be referred to as a Bronco. At this point, the cowboy, whilst maintaining a firm grasp of said mane, yells (in a western drawl): "I have AIDS, syphilis, fleas... ect." Soon thereafter, the Bronco, in a futile attempt to escape the "8 second ride", will start the buckin' process. This is known as the "Buckin' Bronco"!
In a feeble attempt to dislodge my tube-steak from her gully-hole, she flailed and kicked like a buckin' Bronco. Yeehaw!!!
while dukeing a girl, have a friend hide in the closet and suddenly jump out and frighten the girl so much that she will begin to rage around the room while you grasp on to her shoulders and attempt to stay on as long as possible
A buckin bronco is when your friends hide in a closet in a bedroom. You bring your chick upstairs into the same bedroom and start fucking her as your friends listen in and/or watch. You when get her in doggy style you say a trigger word like "sweet" something that is not out of the norm for sex. When your friends in the closet hear this they jump out screaming and one times how long you can ride her as she is trying to buck you off
Brad Pitt and his friends did the buckin bronco to Angelina