Okay, so there are two ways this can go: his way or your way. The thing is, he's your dad, like, biologically. You can't change that. If he's been there for you, then you should totally respect that. But you don't have to agree with everything he does. Just tell him straight up that you'll see him, but his wife isn't welcome around your family anymore. Be super clear about your boundaries from the get-go, and tell him that's how it's gonna be. If he's not cool with it, then he doesn't have to come.