[Gray_Stork]

<Grunch>
Preflop is standard and flop looks okay, too. As weak as it may sound though, I would consider checking this turn. It is quite likely that you're now way behind, or actually drawing dead. Betting here does provide you with enough information to safely check-fold the river, since he calls again. But still, I don't think villain would try to steal the pot on the river even if you checked on turn, indicating weakness. And I think it's very likely that all the worse hands will fold to this bet whereas better hands will raise. AK w/o the spade is the only better hand he might fold against aggression.

Edit: If villain checks behind on turn, definitely bet the river.

Just my thoughts,
Gray_Stork