an altar boy or catholic choir boy who likes to suck the cocks of other altar boys, choir boys, and especially priests.
choir boy: Patrick stayed pretty late with Father O'Brian last week!
altar boy: Yep, Patrick is having a broman catholic cock sucking session with Father O'Brian!
A particularly "chill" Catholic-an individual whose crucifix necklace is only visible because he needs to unbutton his yellow polo in order to pop the collar.
Q: Yo man Is Marty a baptist?
A: No man he's chill, he's Broman Catholic.