Is it okay that I don't want my uncle at my wedding.
I don't know, how does your uncle treat others?
He wasn't nice enough to my dad. He liked sleeping with my mom.
That sounds frustrating. It's understandable if you don't want him at your wedding. You should make sure to talk to him and let him know why beforehand, so he doesn't cause a scene at the wedding.
He cheated on her and caused pain to her. Don't kill the messenger. I tell you this as a warning.
It's your wedding and it's okay to invite who you want. If your uncle expects to come, it would be rude to exclude him without talking to him first.