You reacted badly, even if the dad was a prick. If this was just the first date, it's going to be like that with the dad forever if you decide to stick with the relationship. If you are ok with that, you have to humble yourself and appease the dad and stand your ground when absolutely necessary, such as on things like children and marriage and handling problems. But if you have to fight your ground over a bowl of soup, it is better if she breaks up with you. Not saying you were in the wrong. The dad is retarted and if you think it's bad just imagine how your girlfriend has grown up. She will be greatly influenced by what her dad wants in your relationship too, so you need to decide if you're ok with that. I'd apologize for swearing at her dad and flipping him off, but explain that you don't want her father dictating your actions. Nobody would