First, it is very normal to feel this way. Many women feel this way! Some feel it strongly and others not much, and some don't care. But deep, deep down inside a woman is a survival instinct. It is our job (within the species) to attract the best man we can find, and have a child with him. This is very deeply within us all, although, some feel it more than others.

But this makes women very, very competitive. It is our survival. As a cave-woman, we are smaller and we need to have a man to do the bigger work. He needs to protect us and our child. But, I guess as a joke of evolution, the cave-man's job is to spread his seeds around to the females, and not just one. But, he is also programmed to want to protect his females from other males, because the females he's chosen he feels are worth baring his children. So again, the women are very, very competitive. And the men are very, very protective.

In fact, recent studies show that some women are actually programmed to go after men who are "taken" because they have proven qualities for this survival. And other studies show that some men have less of this drive to seek out other women. So, we all have these codes but in different ways.

I don't know what music you listen to, but that Rhianna song "I want you to make me feel like I"m the only girl in the world...." That is the core of this drive.

This is what I've come down to in my marriage. I am insecure. I think I'm hideously ugly, terrible person. This is me. I know this about myself. My husband isn't a huge porn person. But, at first I got really jealous. Then I realized, he's just looking, it has nothing to do with me. These girls are "imaginary" in that he will never meet them or take them to dinner or have sex. He's just looking. So, I have become okay with that.

But, if it is a girl he knows and talks to in any way (online or in real life,) then that is not okay, not at all, not even a little bit. That is the difference.