Oh man, I actually forgot how dumb this was.
"I let - nay, demanded - my girlfriend be tutored one on one, in her home, by the much older guy who used to tutor her before, and used that as an in with her to start dating and sexually exploiting my girlfriend. After several of these intimate one on one sessions at her home with her ex-boyfriend/sexual exploiter, my girlfriend, whom I haven't contacted much since setting her up with her ex-boyfriend, has decided to break up with me. Yeah, this makes sense and isn't fishy at all." sure is one hell of a plot to write.