I agree that it's your choice whether to wear the rings or not. I haven't been able to wear my rings since my operation (Started out the beginning of the year by breaking my ring finger...now is that foreshadowing or what?!) and if people want to gossip because I'm not wearing rings then I really don't care! There are many valid reasons why someone might not have their rings on.
Just seems like with the situation so fresh in you guys getting back together, even mentioning the rings would kinda put him on the spot and even though it's not a big thing - being a guy he might take it as a big thing....especially if you ask him to wear his. You can't stop gossips if they want to gossip... you might wear your rings and they still might notice some other stupid thing to gossip about.