I think more people have been in your situation than you may realize only most people just live with the frustration and never do anything about it.
I understand how difficult this is since you don't want to damage a relationship that you value very much, but it's a conversation that has to take place sooner or later. Something in your favor is that there are surprisingly many guys who are open to this if they're secure that they're going to lose you.
My ex and I were cuddling after sex (I think it's true that people's defenses are down when they're naked) and she said a friend wanted to take her out when I was out of town. (I had a job with 2 weeks gone and 1 week at home) He wanted to take her to a concert and stay over. She said It didn't mean she was dissatisfied in any way with me and it wasn't a signal that she wanted to break up, it was just that she was young and needed more and I was gone most of the time , and was I secure enough in her love for her to see him. I said okay because I knew she was unhappy when I was gone and maybe this would make things better. Also, I knew that she had had a multiple relationship in the past, and well, she was just her.
There was a period of adjustment as we worked out who would do what with who when, but we stayed together almost two years. It's not to say this approach will work with him 'cuz everybody's different, but I think you recognize who you are and you eventually have to have a life where you can live as yourself. There is, of course, the potential for disaster depending on the person your boyfriend is, but I think you eventually need to give it a shot.
Good luck on the approach.
Last edited by Stevenjaguar; 11-29-2012 at 03:56 PM.