<human>: Could you distill the essence of the text into 1-3 sentences?

My boyfriend of 2 years has a model mayhem account. He has had it for longer than I have known him as he used to be really into photography. He has met a few girls off the site and taken photos of them. I've seen these pictures. They're nothing inappropriate. Mostly artistic photos of a girl looking out a window or something. 

He hasn't done any serious photography in about four years so he doesn't really *need* to have an account anymore. The problem is not that I think he is cheating with any of the girls. He has done nothing to make me think he might be cheating. But I don't think he is logging on to model mayhem for photography's sake either. I believe that he is probably jerking off to these girl's photos. However, this is just an assumption on my part. 

I have no problems with masturbation or him masturbating. But this makes me uncomfortable for some reason. I guess it is the attainable aspect of some of the girls on there. Some of them live in the same state as we do. It takes the whole fantasy aspect of porn out of the equation and makes it more "real," I guess. At least with most porn films, I know that the likelihood of him hanging out with or meeting Jenna Haze is not very high. I almost feel like it would be equivalent to me masturbating to photos of my male friends on facebook or something. I don't know if I am overreacting or not. Am I being unreasonable? How do I even bring this up?
<bot>: My boyfriend of 2 years has a model mayhem account and I believe that he probably masturbates to the girls on there. Am I overreacting by being upset by this?