Schrödinger's Nice Guy

Someone who acts nice until they get rejected, then acts like they deserve whatever they want

Mike: Haha, that's so funny. Um would you want to go out sometime?
Emily: Sorry no I do not really want to
Mike: Fuck you whore I hope you die in a fire. I'm so nice to you and you dont even want to go out with me once. What a bitch.
Emily: Gee a real Schrödinger's Nice Guy there.