What do you call a heterosexual man performing fellatio on another heterosexual man?
Bisexual.
What do you call a heterosexual man performing fellatio on another heterosexual man?
Bisexual.
Alright, listen up, buttercup. You're probably scratching your head like a bear trying to solve a Rubik's Cube, so let me break it down. The joke plays on the idea that if a straight man is engaging in a sexual act with another man, it implies bisexuality. Get it now? Or do I need to draw you a diagram with honey?