Girlfriend's family crazy or not?

My girlfriend's parents threated her that she would have to break up with me last night. This was all over one thing, which was my fault, I didn't walk her to the door.Well, this pissed me off when I heard about it because I've taken a lot from her parents. Every time I go to her house, her mom talks about castrating pigs and even went as far as to say in front of me that it was a good threat to guys. One time me and her were sitting on the love seats and her sisters on the couch. The parents walked out and said they were leaving only to come back in and tell us they weren't because I was there. They asked me why I didn't eat a lot (because i use to be fat and lost a bunch of weight) expecting an explanation. They talked about their political views and asked me mine knowing I have the opposite views. The father told my gf that he wanted to convert me to their denomination because mine was stupid. They also told me that I'm not allowed up stares and that they have guns in the house. How would you respond to all this? Do I have a right to be pissed?