An otherwise heterosexual man who while in prison engages in homosexual sex. Can include who men prefer women but resort to gay sex as an sexual and/or emotional outlet while incarcerated, as well as men who are forced into submissive sexual roles by other men punks.
Jose is straight, married and got kids but he was Prison Gay while he was doing that dime in Attica.
A term that describes men, who by a complete ineptitude with women, often combined with ugly looks, are forced to result to homosexual relationships with other men because they cannot have sex with any women.
Brian and Ford are totally prison gay. Whenever they're not playing D&D, they're having sex with each other because no woman would ever touch either of them.