I think its a matter of manners and discretion here ! At the end of the day its about respect and I for one would not like it much if my partner commented on other girls - it would be rude, I certainly would not comment on another guy being gorgeous to my partner ! BUT - its human nature to window shop and we inevitably do find other people attractive, but we keep that in our heads at the end of the day....thinking about it one thing - braodcasting/acting on it is another and not acceptable IMHO.