<human>: Summarize the given text in a few sentences.

My boyfriend and I have been together for just over 9 months and it has been great. He is great. I have no other issues aside from this one. Now, I know it is normal to occasionally fantasize while having sex, everyone does ( id like to think ). The issue is that he ALWAYS has to and cant finish without it. The other issue being I didn't know this until now and feel betrayed in a way. It makes me feel awful to know that every time we have had sex the thought of someone else was in his head. 

These are woman he knows, not ones he has slept with he says but still woman he knows. Which makes me feel like I am just not enough for him. He says that's not true and that he is incredibly attracted to me , which i never doubted before and that its just how his mind is trained sexually at this point. He tells me all the time how beautiful and sexy he thinks I am, but if that is the case, why can he not finish with just the thought of us,ever? 

Our sex life isn't boring or plain, it is fun, adventurous and frequent and he says its the best sex he has had. This doesn't change how I feel about him, not in the least. He is still the man I want to spend my life with. What I am struggling with here is how to cope, and how to be able to have sex with him without it running through my mind that he probably is picturing someone other than me. Is this normal,  or am I setting too high of expectations?
<bot>: boyfriend cant orgasm to the thought of me while we are together. Has to think about other people that turn him on.