Rare flop overpair fold

[JrJordan]

MP in the hand is a overly LAG player, stats read about 50/20. SB is especially loose passive preflop, something like 40/3 I believe. Postflop though he's more aggressive and has been mouthing off a bit with one of the bad TAG's not in the hand. Hand is in the first/second orbit, so no detailed reads at this point in my session.

Party Poker 10/20 Hold'em (6 max, 6 handed) converter

Preflop: Hero is BB with J[img]/images/graemlins/diamond.gif[/img], J[img]/images/graemlins/club.gif[/img].
<font color="#666666">1 fold</font>, <font color="#CC3333">MP raises</font>, <font color="#666666">2 folds</font>, SB calls, <font color="#CC3333">Hero 3-bets</font>, <font color="#CC3333">MP caps</font>, SB calls, Hero calls.

Flop: (12 SB) 6[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/heart.gif[/img], 6[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(3 players)</font>
SB checks, <font color="#CC3333">Hero bets</font>, <font color="#CC3333">MP raises</font>, <font color="#CC3333">SB 3-bets</font>, Hero folds...

SB could be 3-betting an OESD here, doubtful he'd do it with a 5 or gutshot. I'm trapped between MP and SB; so even if I'm ahead then it's going to cost a lot to get to showdown. FWIW, MP raises this flop with an overpair or UI overcards.