Your hand kind of looks like AK and I'm not expecting any reg to try and bluff you off. We should expect them bet out with all sets on the turn, so I discount all sets from their river value range. Kx just calls the river, as much as I hate to give people narrow ranges, if we assume they are a reg I'm expecting to see a flush here quite often. We could make stronger arguments for calling if we held a spade in our hand.

Interested in what others have to say.

Folding seems fine here to me, it's a vert ambitious bluff if villain is pulling the trigger here without the goods. I would assume most people are flatting Kx here and it seems unlikely they are turning non straight hands into bluffs here which leaves only flushes in villains raising range the majority of the time.

With no reads I'm expecting to be chopping at best. You bet on a nasty board into two players twice so I doubt he's ever playing a bare Kx this way. The price isn't so important here given how we expect micro stakes villains to behave in general.