I'm going to cause conflict in my girlfriend's family
What is your reason for wanting to start conflict?
Because she said they don't like me
I understand being angry at people who don't accept you but you would be proving them right if you caused conflict. They will blame you then your girlfriend will break up with you.
Maybe she will dump me for being rude to her family.
Intentionally trying to create issues for your girlfriend is not a moral thing to do. If you guys are still dating while you are doing this, you are seriously putting your relationship into jeopardy. Being in a relationship with someone should cause you to want them not be in conflict.