Loose Flop Call?

[GTSamIAm]

The Villain here is a fairly passive player. The person on the button is semi-loose and very aggressive. BB is an unknown as he just sat down. Should I have raised preflop? That forces me to lead the flop a good amount of the time into two pretty loose players. Or should I wait until the flop like I did? I checked, folding to the nonaggressive players, and check/raising the aggressive player. Is this my best line here? Should I call the last flop small bet? The pot has to be 25 dollars at the end if I'm gonna win with my set. He likely already has a set of 7's or 3's, so that might happen.

Party Poker 1/2 Hold'em (9 max, 9 handed) converter

Preflop: Hero is SB with 9[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/club.gif[/img].
<font color="#666666">3 folds</font>, MP2 calls, <font color="#666666">1 fold</font>, CO calls, <font color="#666666">1 fold</font>, Hero completes, BB checks.

Flop: (4 SB) A[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/diamond.gif[/img], 3[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
Hero checks, BB checks, MP2 checks, <font color="#CC3333">CO bets</font>, <font color="#CC3333">Hero raises</font>, BB folds, <font color="#CC3333">MP2 3-bets</font>, CO folds, Hero calls.

Turn: (5.50 BB) T[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP2 bets</font>, Hero folds.

Final Pot: 6.50 BB