[TheDudeChad]

If you were confident enough that villain would raise KK-88 on this flop and bet the turn into 3 callers, then the river looks like an easy CR since your hand looks like a flush and a hand like KK couldn't pass up that value bet.

That said, I think its very unlikely that he does have KK-88 given the flop and turn play. I think its reasonably likely he could have raised them on the flop, but once he gets 3 callers he has to believe at least someone has an A. That would be a pretty bad turn bet. On the turn I think his most likely hands are a better A, a flopped set, or a flopped flush, then KK-88.

So, like others have said, just call turn and donk river.