I think we have to call river.
We are probably in the top half of our range as we have a load of single c-bet air and our only good hands are aces that c-bet and gave up on turn (I would also check back flop here - its too hard for them to float when we bet into 3 players so we can't get many streets of value against worse).
Given the above, while he may well reach river with a better K he shouldn't bet it out against our polarised range. If we're really folding hand strength of K-rag and lower here then a bet makes no sense with a strong K - particularly when we should be thin on Ks.
Obviously we lost this hand as otherwise it never gets posted - I'm guessing he may have floated with an A, particularly A
, or called flop with a mid pair and A kicker (perhaps A
6
) and rivered 2 pair - or somehow backdoored a flush on us (though worth remembering that the A always blocks a lot of the suited club hands that actually see flop) - but that doesn't change the fact that he should bet this with all kinds of trash and we need to bluff-catch all of the few showdownable hands we get here with.