6/12 Borg - KK question

[anisotropy]

I was down on 12/26 playing 6/12 at the Borg when this hand occurred. I had been at the table a while, as had everyone else except the new guy I was up against. He had been there maybe a half hour and I hadn't seen him play too much except a few monsters. He rarely limped in, though.

I am in the SB with KK. MP1 limps, villain (button) raises and I 3-bet it. Everyone drops except BB and MP1 and villain.

Flop: 7 /images/graemlins/spade.gif 8 /images/graemlins/diamond.gif 3 /images/graemlins/club.gif

Action is bet, fold, call, call. So now we're heads up.

Turn: 6 /images/graemlins/heart.gif

Rainbow is complete. Action is bet, fold, raise by button (?) and I'm really confused. I think for a second about 3 betting, but instead just call. Is this bad? I don't think I should consider folding but I'll listen to arguments for that as well.

River: T /images/graemlins/diamond.gif

I really don't like the 4 straight out there and check. He checks behind and <font color="white">shows AJd and MHIG.</font>

So questions are: should I fold/3-bet the turn? Should I bet the river? How badly did I misplay this?

[cold_cash]

What hands are you worried about?

His lack of a pre-flop cap makes AA less likely, and the only hand he can have that contains a 9 is 99, no?

The Ten on the river kinda sucks, but I would 3-bet the turn for sure. If he raises the turn I would call it down, otherwise I'd bet and call on the river.