@Tristen Monroe,
You're kidding, right? Is there a reason he cannot go by himself? So, just out of curiosity, if you couldn't go out with him to a movie tonight, he'd go out with some other girl? Does not sound like much of a boyfriend to me.
Speaking of course as a guy, I wouldn't be happy with a girlfriend doing this at all. I'd be quite upset about it if I were you and I'd let him know you don't like it at all. But then, I'm kinda old fashioned and much older than I think you are. You youngsters nowadays surprise me with what you accept from a "boyfriend/girlfriend."