There are things in relationships that a man will let slide but a woman would have to make an issue of. Plus, women in relationships remember EVERY.LITTLE.THING. that happens in that relationship, whereas men will forget (if not forgive). Times that by two and I think you are a long ways towards figuring out the disparity in numbers here.
...but then again, "lol men!" so we're probably going to take sh**t from the ivory towers for even considering discussing this subject.
It'd be a crying shame to miss more stunning insights/regurgitated clichés.