1. a cock blocking friend.
2. a friend who always tries to have sex with the girl your trying to get with.
3. a friend who tries to have sex with your friends.
4. a friend with great sexual impulses.
Nate: man, Morris is suck a dick-friend.
Tye: yeah, he tried to steal my FwB
Nate: he cock blocked me last night...
Morris: hey, whatsup? where's Rachel?
Tye: go f**k yourself.