Nope. With a set of K on that board, I'm betting for value there.
I'm not terribly worried about the flush in that spot, being that there aren't many flush hands he can conceivably have there. Q
J
is a possibility, but I feel it's more likely he has a hand like AxQ
or AxJ
and thinks he might have the best hand still.
Of course, if he raises the river, the decision is tougher, though I think I'm still calling bar some physical tell or read.