Hey

Was wondering what is the optimal play on the flop?

6 handed game NL50

UTG halfstack 25/21/7 opens for 2.2 bb. He opens very wide UTG, 20+%

CO reg with 100bbs calls

BTN: player thats looks like an loose spewy fish 3bets to 10.5bb

His stats after 50+ hands hands: 41/30/3b=29, he sqzed once after 1 opportunity.

Hero is in the SB with As Qd. I hate calling here and letting 2 more players in, so decide to clickback to 21bbs. I feel like no one is going to 5b anything worse than AQ ever here, including BTN. I expect a player like him to call with close to 100% of his range, maybe exept AK that he shoves allin preflop for sure. Not sure about monsters like QQ+. I feel like he ships them quite often too, because players like him do not tend to be tricky, but overaggressive. His fold to 3b=0%. 

Folding preflop is obviously ok considering there was an open UTG, but I feel like there is value in playing with BTN. Besides, we're risking 11$ to win like 8$. Does anyone fold here? 

BB folds, BTN instacalls.

BTN afq flop 38%, af 2, WTSD 44%, fold2cbet=0% (0/3)

Flop: 9s 8h 3s. Pot is now 25$ (50bb) and we have exactly 39$

Hero? What is the optimal play and why?