You could tell him if he wants to take you out he can take you out to church, or tell him you are a platinum lesbian and quickly scurry off. You should be careful when using these lines as some men can turn violent when given such responses.
You know how these guys are. They think "no" means "yes" and "get lost" means " take me I'm yours". Just be like " oh, you want to go out with me? Can I bring my boyfriend?" Or " I don't think your bitches would like that very much" or "sorry, I can't. I'll be busy living my life. You should go get your own"