Why would they fight, they could both be xenosexuals.
Pred could give Alienchick some bloodflowers, they could have some wonderful candlelight dinners together and talk about decapatation, Pred could show AlienChick his bone... collection and they could get married and have a long and happy life together.
Mind you, the bedroom scenes paint a mental polaroid that I could do without.
I saw it opening day here in the states (8/13). It is a good movie. Love the video games too. There are a few things about the movie that could've been better, or don't make much sense, but for what it is, it's cool.
I won't give the movie away, but for my vote aliens are the coolest thing sinse kinky sex and hard drugs.