Turn and River- what level of agression?

[Casey]

5limpers to me and I complete in the small blind with j-8 of spades. BB raises. BB is fairly new and known to sme of the others at the table to be gambler, I have never played with him before. All call his raise. For those of you that frequent CP, his name is Simon and he deals BJack at Mystic, from the conversation around the table,he mostly plays stud.

Flop comes 10-9-3 with two spades. I check, bb bets and everyone calls, I check-raise, bb three bets and everyone calls.

Turn is Q hearts, completing my straight, i check bb bets, 2 caller, i check raise, bb 3 bets, lose both callers, i four bet and bb five bets. This is where I am wondering. I am ahead of everything but KJ and I have the spade redraw. By this time we are heads up and I could have raised again. Who stops at 5 bets here?

River is A or spade and I bet out and get raised. I call. Who pops it another time?