Porn is to men as Twilight is to women.

You like reading stories and imagining a big, strong, dangerous but caring, immortal, twinkly protector who for some inexplicable reason bothers to hang around a whingy, vapid, 2-dimensional high-school girl.

We like looking at images or videos of naked, unashamed, female bodies willing to pose themselves so we can see exactly what we want to see, and who will pretend to enjoy doing so.

The images we're looking at no more represent "real people" in our minds than Edward represents "a real person" in your mind. Porn is as much a threat to you as "Edward" is to us - just as only someone truly stupid would dump or denigrate their (real) boyfriend in favour of a fictional character, only someone truly delusional would dump or denigrate their (real) girlfriend in order to go looking for women based on illusions created by women who are paid money to appear always available for sex 24/7 and/or pretend they're having fun in a variety of uncomfortable poses.

The only difference is that our fantasies are slightly more to the point, visual instead of imagined, and they're slightly more realistic.