Perhaps you assumed he would wear it that way but sometimes we think guys are going to do something a certain way and they didn't have a clue. Suggesting that you are both in possession of a token when he gave you back your ring will perhaps appeal to the equality of the situation and not quite seem as if you are being the aggressor. If he still says no. I would say that he must have some reason that makes sense to him. He is probably telling you the truth since he could choose to take it and just not wear it. He choose instead to tell you he would rather not.
