Queens overpair, weird betting patterns from opp.

[trumpman84]

PokerStars 1/2 Hold'em (8 handed)

Preflop: Hero is CO with Q[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/diamond.gif[/img].
UTG calls, UTG+1 folds, <font color="CC3333">MP1 raises</font>, MP2 folds, <font color="CC3333">Hero 3-bets</font>, Button folds, SB calls, BB folds, UTG folds, MP1 calls.

Flop: (11 SB) 5[img]/images/graemlins/heart.gif[/img], 3[img]/images/graemlins/heart.gif[/img], 7[img]/images/graemlins/club.gif[/img] <font color="blue">(3 players)</font>
<font color="CC3333">SB bets</font>, <font color="CC3333">MP1 raises</font>, <font color="CC3333">Hero 3-bets</font>, SB calls, MP1 calls.

Turn: (9 BB) 9[img]/images/graemlins/spade.gif[/img] <font color="blue">(3 players)</font>
<font color="CC3333">SB bets</font>, <font color="CC3333">MP1 raises</font>, Hero ??

At this point I'm thinking my queens are behind. SB cold called pre-flop and is stopping and going at every street. MP1 didn't show any real strength pre-flop by choosing not to cap, but I'm thinking he might of caught a set because he is continuing to raise at every opportunity. Ok to fold here facing two bets cold? Or call down?