Pegging my finacé

So I've wanted to do this for aaaaaages and he came around to the idea, he's always been really open to trying new things and because of it we've experienced a lot of fun things together. The problem is that I know for a fact that he doesn't get turned on by the idea, which is part of the enjoyment for me. I also don't want to hurt him or do something to him that we regret - and TO him is definitely the right wording, he would just be taking it but not enjoying it. I don't know what to do...