The real question should be why are you so offended by this entire idea of recognizing inappropriate relationships regardless of whether humans are involved or not? Yes, these are aliens. Yes, I'm applying human standards to aliens. That's what all of these TV shows are, allegories to human situations. The entire reason we have forums like this is to talk about these human situations.

You can upset and run away all you want. All it does is kill the conversation, which I guess is what you wanted anyways. But it still doesn't change the fact that this is humans writing stories about aliens, not actual aliens. Applying human standards is not a bad thing.