A man who is not necessarily gay outside of prison but engages in homosexual acts in prison as the giver (i.e the pitcher) instead of the receiver (i.e. the catcher). Prison straight is a form "justified" homosexuality.
Dude, Tarig is married but he got drunk last night and slipped Dave his hot salame. He's not gay but he's definitely prison straight because he was the pitcher.
by Kramm December 12, 2007