What is your flat calling range here pre? Often with your line, it's just so obviously something like 99+, AQs, AKo. It's why I hate flat calling here pre. You can't balance your range here that easily.
But anyway... Probably have to bet. Doesn't need to be too large given it's multiway and you are blocking the thick value hands. SB can easily have bigger overpairs and range checking this board. UTG can also have hit a set or have just total whiffs with broadway hands. We have equity against the sets and overpairs. The only issue is that you betting here basically looks like you have exactly what you have. You can't have nuts though, and you can't really have all the sets. Just a crappy spot.