I'm going to leave dinner with my gf and her parents
Why are you leaving dinner?
Because I'm not in the mood to see her judgmental father.
It's rather rude to leave a family gathering early like that. You should at least sit down and eat with them.
Her father just irritates me to no end with his judgmental looks and passive aggressive comments about me.
You have a right to feel he way that yo do toward her father. But walking out will just make him look justified in being judgmental about you. Stay for your girlfriend's sake and to not prove her father right about you.