Should I set myself up for the trifecta?

[J.A.Sucker]

80 - 160 game. My opponent is a total wacko and loves to play the game, moreso than he likes money. I say this because he does all kinds of wacky things just because they are fun, not necessarily because they are right. The best thing is that he actually realizes this and doesn't care. The non-California players know the type of guy I'm talking about, but I don't know if the others do. He's a nice guy and we have some good banter going.

He opens for a raise in the SB and I 3 bet with 66 in the BB. He calls.

Flop comes: 8-5-3. Rainbow. He checks, I bet. He checkraises. I call.

Turn: 8. He checks again. I bet. He checkraises again. I call again.

River: Q. He checks. I do what?

Comments on all streets welcome.