RockRose nailed it.
Men like to look at strange boobies. Women don't necessarily like to look at strange __________ (insert appropriate word here).
Men, by their very nature, are stimulated by the visual, whereas most women are stimulate by the emotional.
There's not a lot more to it than that.
Sorry, I basically repeated what RockRose said.
I love my partner (girlfriend) very much, and would NEVER consider straying from the outlined, identified, mutually agreed upon "boundaries" of our relationship. But don't think for one second that seeing an attractive woman naked wouldn't possibly arouse me. Would I "do" anything about it, if it happened? NO. Would I have "thoughts" going through my head? Most probably YES. Does that make me a bad person or a "cheater"? In my opinion, NO (I'm sure there are those that would disagree, and say that if you even THINK about sexual acts with someone who isn't your partner, that you're cheating, but I personally don't subscribe to that line of thought).
Sorry to drone on...
I didn't see my answer there - men want to look at naked pictures of women they don't know, and women don't want to look at naked pictures of men they don't know.
It's a brain thing, a visual thing.
The one porn magazine that was directed at women, "Playgirl" was bought by women as gag gifts for bachelorette parties, and by gay men.