inbonerable
to not be subject to feminine wiles, to be able to not get a boner despite major advances by a girl or flirting
Guy 1: Dang, that girl was coming on to him like crazy. He probably has a huge boner right now.
Guy 2: Nah, probably not. That guy is inbonerable.
Guy 2: Nah, probably not. That guy is inbonerable.