Middle set against possible draws

[Worrots]

This is from the 2+2 table Monday night. Opponent is 38%/10%/0.83 in ~150 hands. So, he's not so choosy in starting hands and tends to go passive post-flop.

I'm aggressive with my middle set until the the turn and then go passive when he raises again with the scare card on board. At least, I hung around for the showdown.

Party Poker 0.5/1 Hold'em (10 handed) converter

Preflop: Hero is SB with 4[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/club.gif[/img].
UTG folds, UTG+1 folds, UTG+2 folds, MP1 folds, MP2 calls, MP3 calls, CO folds, Button folds, Hero completes, BB checks.

Flop: (4 SB) 3[img]/images/graemlins/heart.gif[/img], 4[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(4 players)</font>
<font color="#CC3333">Hero bets</font>, BB folds, <font color="#CC3333">MP2 raises</font>, MP3 folds, <font color="#CC3333">Hero 3-bets</font>, MP2 calls.

Turn: (5 BB) 7[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">MP2 raises</font>, Hero calls.

River: (9 BB) J[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">MP2 bets</font>, Hero calls.

Final Pot: 11 BB

I was thinking he could have the over set, but, in retrospect, then why wouldn't he cap the flop? Worry #2 was him pumping a straight &amp; flush draw. Plus he's usually not aggressive post-flop and here he's raising on the flop and turn. Of course, it was a 2+2 table so aggression is the norm.

Thoughts on my turn play? I wasn't going to give up the river for one more bet either way.