When a man is under complete control of a girl (or group of girls) that isn't even their girlfriend. Or to put it simply, when someone is completely whipped, yet is single. In most cases, you may as well remove the mans testicles because they either belong to the chick, or are long gone. In most cases, if caught early, the man can be saved. If not, there's no getting him back.
Wow, Sam does whatever that girl tells him to, and she's not even his girlfriend. He's so uniwhipped.