If we call there will be 487 in the pot and he will have 310 left (we cover).
A flush is not that likely especially given our history. It looks like he is scared of being bluffed off the hand and to be honest we would have bet/called a jam on this turn anyway. His most likely holding is pair of Kings + a flush draw or some kind of straight/flush combo draw like A
J
. He could even have air.
I just jam and hope to get called by worse.
If it was a more aggressive villain, I would consider calling to keep all his bluffs in and call a shove on any non-
river. But I'm expecting this guy to have some kind of equity and to be capable of giving up if he misses his card on the river.