[spino1i]

It would help to know what hands he has showdown when he has taken this line in the past (checked behind on flop, bet turn). Its different for different players, though its generally a medium-strength hand. In this case, I'd say its likely to be a K (in a vacuum) unless he is mixing up his game reacting to your playing style. So I'd say a 3-bet with intention of betting any river is actually a pretty good idea here, because I think a K would prolly fold to that much pressure. I like it.