Turned on when hubby checks out other girls

For some reason it turns me on when my husband looks at other women. Especially if I think they're attractive too. It's to the point that I will find really hot pictures of women I think he would like, and show them to him just to see his reaction. I also love watching girl on girl porn with him for the same reason. It's not that I don't turn him on, I'm young, 22, and in shape. I consider myself attractive, but there's always someone prettier... IIN?