Flop bottom set - slow down?

[Xhad]

Based on numbers, I wouldn't expect either individual to have you beat. However, the probability that MP1 made a retarded pf limp with KK or QQ is probably greater than the probability that they both have KQ.

I would not slow down if they weren't both still betting on the turn (essentially removing draws from their ranges), but as it went down I think the river is a c/c.