But the woman isn't homosexual? We talk about a fictional woman in this song, who he tries to portray as undicided bisexual.
When the woman in the song is homosexual or bisexual, then i agree, it would be homophobic. But he tries to portray her as experimental. He clearly failed in painting a clear picture.
I'll just copy my previous post:
It doesn't matter whether she's bi-curious, bisexual, straight or gay, what matters is that the song literally says that the 'main character' can fuck the 'gay' out of her system.
I'll add that it essentially makes bi-curiousity into not a complex and deeply personal matter but an 'infliction' that can be fixed if the right man/woman (almost always man, of course) comes around.
EDIT: There's also this:
Forget the "fuck you straight" phrasing for a second. She said she's into girls and yet he's still trying to fuck her. That's bad enough, choice of words notwithstanding.