I think a man is just more likely to say "that's my wife/gf and I gotta ride this out" when times get rough. You always hear about a woman stepping out when she's not feeling loved or whatever it's rarely just ineedsumdik.

It's peculiar because in the old days women putting up with their man's bullshit is what kept marriages together.

I don't know if that necessarily translates to being less faithful, but it's a unique type of unfaithfulness.