personally, I'm fine with calling it "reverse" rape. It's commonly believed that rape is a predominantly male action, to the point that a lot of people mistakenly believe that it's impossible for women to do so. Regardless, male-on-female rape is clearly the standard, so therefor, it makes sense to refer to it as a "reverse" of that standard when girls are the one doing it to guys (besides, would you rather everyone just went around calling it "female-on-male rape"?).