I think you’re being a little narrow minded. Rape and incest jokes are not okay, and if they make you uncomfortable then you should tell your gf to talk to her dad about how he acts around you. But the other stuff? Playing cards against humanity together? Not a big deal. The incident when your gf was 16 sounds resolved, her dad apologized, that’s between your gf and him. If you like this girl and she doesn’t have issues with her family dynamic, then I’m sorry but you’re going to have to find a way to tolerate her family. And maybe it starts with accepting that some people are more open with their family about sex than how you were raised