The ethical slut is a great book for some but be warned giving it to someone who is not interested in open relationships of any kind. It doesn't go over well in my experience. There is discussion on some really great books in the stickies "book reccomendstions."
I would suggest giving it to him for Christmas. I'm not sure why you are doing all the work to be okay with this new possibility and he isn't. He has more work to do around this than you I think. Speaking as the one in my relationships who is with two men who don't have other partners, just me, I have a shit load of work to do to make sure that nothing goes a miss and I am making sure my attention is directed approriately. He has a lot to learn before he ventures out and fucks someone else. The whole world can change after that, I think he needs to be prepared for that likely reality as much as you do.
Quite often there is a huge shift when we give our bodies to someone else. The vulnerablity of sex with others is huge and I think shouldn't be taken lightly. It can be normalized and is sometimes not as big a deal for some over others, but one doesn't know until they are in it and its happened. I mean let's face it, would this forum be as frequented if we all could blow off the connection that we as humans have to sex with others and the connection it brings? Maybe on swinging sites that happens, but something tells me that on sites like those (having never been and found out) that sexual energy is internalized and turned into fun rather than connection.
I think its great you are discovering this FOR you man, but I think he needs to discover it for you too. I think it time he was more involved in this process. To me, to not do so would be na´ve and risky.
Anyone want to be friends on Facebook?
Send me your name via PM