If men wearing women's clothing are an insult to women then I guess women wearing men's clothing must be an insult to men. The logic is the same so if it is valid in one case then it must be valid in the other as well. However, clearly most women wearing pants are not trying to 'impersonate' a man, whereas most often when a man is wearing women's clothing they are trying to impersonate a woman. However, if they aren't just clothes then the next time she wear pants, suits, ties, tell her she is looking too manly and you are insulted. This probably won't win you many sympathy points so don't really say it as if you mean it!
