I'm not going to invite my brother to a trip I'm taking with my girlfriend and parents
Why you not want to invite your brother on the trip with you?
He doesn't like me and he's disloyal.
You should invite him. Family should always be invited to family events, even if you don't like each other.
He's a bastard.
But he is also still your brother. You need to include him in family events even if you don't like him.