Girlfriend talking about other guys?

My girlfriend likes to talk about other guys, I'm not gonna lie. When four of us are hanging out, her, me, her friend, and my friend, her friend and her go off about how they'd "lock this actor in a bedroom and screw his brains out." I don't really care, cause I'll be honest, I'd do that to a bunch of actresses as well. Anyway, but they also go on about people we know...we've heard them say that one of their friends has the "nicest body imaginable." Furthermore, it doesn't bother me, but today, my friend and I were talking about this nice looking girl we saw (I didn't bring her up), and my girlfriend flipped one. I told her she's being a hypocrite, and she starting getting offended and emotional. Obviously, if she can talk, so can I, right? So, the discussion went on, and she told me that, "yes, I agree he has a VERY nice body," during the argument, so I told her my body is off limits if she likes his so much, and that's how I feel. Am i overreacting about this at all?