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Specifically sexual attraction is what I'm guessing and to be more accurate what I'm able to answer to some extent. I'm not aware if is the same for women however as a guy the immediate sexual attraction is somewhat instinctual, I know it sounds like a cover but I've been in wonderful relationships where I was not remotely interested in other women and yet still I would see a figure in the corner that would make my neck snap sideways all on it's own, I'm not to proud to admit that I've fallen for a well shaped lamp post from time to time. I would get embarrassed when I got caught.
I think anything beyond that is simply a lack of will power and consideration brought on by men using their gender and the sexual acceptance that goes along with it as an excuse to act impulsively.