eff stacks ~3.5k

hero raises UTG 100 QsQh

SB calls.

Flop Qd9d2h

SB checks, Hero bets 120, SB calls

Turn 10c

SB checks, Hero bets 240, SB raises to 680.

*SB is lag and capable of moves, and was having a losing sessions so he was attacking pots alot.

**What do you do after this raise?? Put him on a set and reship? Put him on a bluf and ship/loose him? Put him on some sort of draw and then what, raise or smooth call? Or obv put him on KJ/J8 and just call hope to pair the board??

Well it doesn't end here, I ended up just calling

River 4d

SB leads out for 300. WTF???????

My first instinct was that he didn't like that card and was making a defensive bet, then i realized maybe he was trying to induce a raise from me since he saw me bluff raising river before, but i decided he did not have a flush because i was credibly representing a strong hand and he would miss value with such a small bet .. Then the thinking process started, I actually tanked for a while..

 First I thought about raising him to get some thin value from some of his set and few of his 2p then started to think about the str, and thought about making an over bet trying to rep the flush for him to fold, then decided that would never work and ended up just calling.

I know its not a huge pot but I really got lost on this hand. What do you guys think the profitable play is and would you do any part any different??

Cheers