My GF wants to fuck gays and openly asks them to do it.

So we were laying in bed last night, in between sexytimes. She starts telling me this story about how she wants to fuck her cousins gay-friend's boyfriend. The BFs were talking on the phone (over the holidays) and she started talking to him saying that she wants to wear a strap on and fuck him with it gay man style. I start freaking out but she keeps insisting its okay for her to hit on gay guys because they would never want to go through with it.

I think its rude. What should I do?