KK on ragged flop when raised and reraised?

[KnickNut3]

Hello. Through about 50 hands both players are sL-N, with VPIPs of ~22 and PFA of 1.5 or so. No better reads because I'm playing 5 tables.

Party Poker 0.5/1 Hold'em (8 handed) converter

Preflop: Hero is BB with K[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img].
UTG calls, UTG+1 calls, <font color="#666666">4 folds</font>, SB completes, <font color="#CC3333">Hero raises</font>, UTG calls, <font color="#CC3333">UTG+1 3-bets</font>, SB folds, <font color="#CC3333">Hero caps</font>, UTG calls, UTG+1 calls.

Flop: (13 SB) 6[img]/images/graemlins/heart.gif[/img], 9[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
<font color="#CC3333">Hero bets</font>, <font color="#CC3333">UTG raises</font>, <font color="#CC3333">UTG+1 3-bets</font>, Hero ????

Someone sure is raising like they've got AA (especially on straightforward party 5/1), and if one of them has it I'm drawing to 2 outs. Should I fold? With it capped preflop and a ragged board, could anyone have anything else better than KK besides AA? Especially with the limp-RR preflop?