Thanks for the replies
Books and movies should be great conversation starters. Your list was very helpful, drtalon. I have a few movies in mind that I want to show him and I will definitely check out Summer Love.
My boyfriend is open minded so I hope he will at least consider a poly lifestyle with me. Although I am still concerned about the possibility of him becoming jealous of my other relationships if we do decide to go poly. At least now I have some resources and knowledge on how to deal with the initial conversation.
Baby steps, right?