Not that this is necessarily sexism but I do loathe those kind of situations when a man is expected to do this and that, just because he's a man. Like for example "oh you're a guy so you have to buy me dinner" or just a plain passive attitude from a woman because "a guy should be doing this instead"

So yea, using your gender as an excuse for certain things..not good

Doesn't matter what your gender is, you still can't completely avoid these silly stereotypes