Am I being weird or is he? (NSFW?)

I hate posting personal problems here, but I need some insight. Today, for some reason I looked at my SO others phone. I saw tons of messages to porn stars saying he would like to write an eBook for them. (He writes small time, not big stuff).

The topic was to be about their sex life. What turns them on, how they enjoy oral sex, the positions they love , and to please send some photos.

Okay I admit, I freaking mad. Am I out of line? I never trust my own emotions is the point. He says it ‘was a surprise’ he was going to talk to me about after he had made money from it? Why not tell me why he was doing it? That is my question. I really could do with some thoughts and please don’t hold back either way.

I’ve been having physical health problems for a while now, so basically he is sex starved if I think about it.

(If you think I am being an ass say so).