JJ vs donk-bet on lousy turn

[SkittleBrau]

Eurobet 3/6, 5max/5 handed.

Hero is CO with J[img]/images/graemlins/diamond.gif[/img] J[img]/images/graemlins/spade.gif[/img]

UTG alternates weirdly between LAG and LP (43/22/1.8) and is unpredictable and hard to figure out.

Button is pretty new but has been very tight so far and not too aggressive, but has been playing reasonably up to this point from what I have seen (18/8/1 but few hands).

Preflop: UTG raises, Hero 3-bets, button calls, blinds fold, UTG calls.
<font color="blue"> If it's not a misclick, I'm not sure what range to put button on here. High suited broadways or decent PP?</font>

Flop is 10[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/heart.gif[/img] 2[img]/images/graemlins/heart.gif[/img]
UTG checks, Hero bets, button calls, UTG calls.

Turn is (10[img]/images/graemlins/spade.gif[/img] 5[img]/images/graemlins/heart.gif[/img] 2[img]/images/graemlins/heart.gif[/img]) K[img]/images/graemlins/heart.gif[/img]
UTG bets, Hero ?
<font color="blue"> Based on his past play, UTG might have just picked up a draw or have called the flop w/ nothing and suddenly decided to bluff. But he also could have just hit kings or have been slowplaying something big on the flop like a set. Button has taken a weird line so I really don't have a good idea of what he might have (something with a king would not be suprising, however).</font>

[hemstock]

Ugh... really tough decision.
I would propably raise for a free showdown. If he 3-bets or donks the river, you know what you have to do.

[LoaferGee12]

I think we can fold this. Given the prior action and that there are 2 players to act behind him, I just don't see what you beat at this point.
If I am calling this, I think raising for a free showdown is our best bet, as hemstock said.