I don't want my daughter's boyfriend at my other daughters wedding
Why are you excluding your daughter's boyfriend?
I don't like him at all. He doesn't treat my daughter well and he's also a huge asshole.
It's good that you are trying to protect your children, but it's also important to let them live their own lives. If you interfere with their relationships, they might pull away from you. I'd hate to see your relationship with your daughter suffer over this.
I'm not always an idiot. I can put my foot down with this one as I don't want to see my other daughter get cheated on.
You shouldn't dictate guests at someone else's wedding and you shouldn't tell someone who they can bring. As hard as it is you need to let your daughter decide how she will be treated.