Meg is a blooming genius:

"We women can be pretty sensitive and most of us don't like competition. Especially air-brushed, fake perfection that we could never aspire to. When a man feels the need to look at naked women who aren't us, we think that we aren't good enough ourselves."

And I think it's doubly true when men look at porn that has nothing to do with their own personal sexual style. Women always think they aren't good enough - you know, if they looked like a porn queen, maybe their man would want to do X or Y....