A male who enjoys pleasure up the ass. May refer to him being homosexual or just liking anal. Also could be a boy wanting threshold.
Susie: Ohh I wanna tap Henry, maybe i should seduce him tonight.
Bridget: Not Henry! Hes a bumboy!
Susie: I didn't know he swings that way. What a shame, hes so good looking.
The act of being able to take two penises in one's rectum at one time, with a smile. Named in honor of its esteemed founder, "Bumsoil", of the ever growing homosexual pornography business.
John, new to the business, was eager to start his career in the gay porn business, so he pulled a "bumsoil" in his first ever video and instantly won the respect of his peers.