(n.) a person of the male gender that is in jail and is being used as an item. The term usually aplies more to convicts on the smaller or younger side, who cannot defend themselves in the "clink". They usually get raped in their cells or in the shower. Sometimes, there is a ring of fuck boys, in which these people are passed around from the bigger, badder convicts, so they don't get raped by "strangers". They also do it for the everyday protection of the very bad things in jail. These fuck boys are also referred to as "bitch", such as:
"Hey! You're my new fuck boy. Your my bitch now. Bend over."
"Oops, you dropped the soap...now bend over and pick it up, fuck boy."
"So, you're the new fuck boy on Cell Blck B? Welcome to the ring."
Basically, the whole ordeal is pretty fucked up.