Slang word for jail. It's called that because of the many rapings that go on between the inmates in there. As a matter of fact, that's why they call them inmates. Once you're IN jail you'll be MATING with one of those motherfuckers.
"Because Brad insulted Jessica, his once available bootytunity is now lost."
"Kelly's parents went out for the night. She fully took advantage of the bootytunity and invited her boyfriend over for a sexy rendezvous."