I was thinking about a CR in this hand but was I better off staying the aggressor in this hand? And what the hell was MP3 thinking???

PokerStars 0.10/0.20 Hold'em (9 handed) converter

Preflop: Hero is MP2 with , .
1 fold, UTG+1 calls, MP1 calls, Hero raises, MP3 3-bets, CO calls, 3 folds, UTG+1 folds, MP1 folds, Hero caps, MP3 calls, CO calls.

Flop: (15.50 SB) , , (3 players)
Hero bets, MP3 calls, CO calls.

Turn: (9.25 BB) (3 players)
Hero bets, MP3 calls, CO calls.

River: (12.25 BB) (3 players)
Hero bets, MP3 folds, CO calls.

Final Pot: 14.25 BB

Results in white below:
Hero has Qd Qs (two pair, queens and twos).
CO has Ad 3d (one pair, twos).
Outcome: Hero wins 14.25 BB.

I wouldnt check raise into that board. The pot is too large that your CR isn't going to deny odds of drawing the flush. If someone had the trips they would have been nuts for playing the cap with 2x. They also would have reraised you. The best you can do is jam with what you have and hope overcards and the flush dont hit. You played it well IMO.

Played just fine.... Best case scenario, you gain 1 bb from CR'sing the flop. Most likely you will break even since MP3 would probably fold on the turn, hence losing his BB call.... Then again, another very possible scenario is it gets checked around on the flop. CO is such a fish that hes not bettin nuttin.

You can't check-raise when you put in the last bet preflop. Well, you CAN... but you'll lose out on the flop bet more often when it gets checked around then you win the extra bet with the CR.