1 : of, relating to, or characterized by a tendency to direct sexual desire toward another that is strange, foreign, or alien
2 : of, relating to, or involving sexual intercourse with an alien or foreigner
3 : a person that has sex with aliens or foreigners
Bob : Did you see that Zeta Reticulian? I so want to get a piece of that.
Sue : Geesh, you are such a xenosexual, Bob.