Is it not totally obvious? Someone who's been raped feels extra vulnerable as a result. So a sexual reference, when not coming from a man she wants sex with... come on, joining the dots isn't really that hard is it?

I don't really understand what you're trying to argue, but promoting "sex is okay" isn't really a defence because that's not the point. The point is that certain things make certain people feel vulnerable, and potentially for good reason — the way to change that is to make the world safer for those who might be at risk, not to tell them their fears are unfounded.