When you duct tape a large chested female to the ceiling or any other suspended point (with her consent and zero harm involved) and proceed to use her knockers as speed bags. Can be used as a training method for you and a form of stimuli for her.
v. - to ejacualate in a girl's mouth and before she has any time to spit or swallow the semen, proceed to throw her a haymaker to the side of the face and watch the semen fly out of her mouth.
(ala the blood from a boxer's mouth when he is punched hard enough)