I really hate getting in spots like this with jacks. BB in this hand is a total fish, no info on button. I really hate playing a bloated pot with just Jacks.

PokerStars No-Limit Hold'em, $0.50 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

CO ($8.75)
Button ($52.90)
SB ($57.85)
BB ($68.05)
Hero ($50)
UTG+1 ($24.55)
MP1 ($55.85)
MP2 ($28.25)
MP3 ($45)

Preflop: Hero is UTG with J, J.
Hero raises to $2, 1 fold, MP1 calls $2, 3 folds, Button calls $2, 1 fold, BB calls $1.50.

Flop: ($8.25) 4, 9, 8 (4 players)
BB checks, Hero bets $5, MP1 folds, Button calls $5, BB calls $5.

Turn: ($23.25) K (3 players)
BB checks, Hero checks, Button bets $11, BB folds, Hero?

Bet more on the flop, your hand is very vulnerable, as you discovered on the turn. Now you have to dump it.

As played you have to fold the turn.

Only thing you can do different is figure out what you're willing to call on the turn and lead out with it. Button may put you on AK. But judging by his flat call w/action behind him, I think you're dead to a set here, or at least way behind a K.

fold the turn? what? He could easily have a pair of 9s, 8s, or even a draw, and it gets checked to him. I'm calling the turn and a reasonable bet on the river. That or donking the river for a cheap showdown. Only conceivable hand that has caught up is K9.

We raised and got three PF calls. We bet the flop and got two calls. We're beaten by at least one of them now.

I probably would have bet the flop bigger. Then maybe lead at the turn as well.
If you contiuation bet the flop and missed then checked the turn he would bet his 9 here.
He probably thinks you missed. He would not be betting so big with k9 top two.

But one of the callers folded, so we only need to beat the button, who made a small bet after weakness was shown on the turn. Had BB also called the turn, I would lean more towards folding, but as is, I think a call is reasonable. The problem of course is that most river cards scare us, so I am not sure what the plan is then. But I think folding this turn is too weak, unless we are against K9 or KcXc we are still ahead.

What are you ahead of with JJ that called a PF raise, called a flop bet, and is now betting into us?

The only hand I can think of is a suited QJ or some sort of combo draw with a low pair. But those hands certainly don't reopen betting on the turn if they were too nitty to push the flop.

AcXc, A9s, TJs, 9Ts (with the suitedness not necessairly clubs) all come to mind of the top of my head. The thing is, we could have any sort of AQ, AJ, etc that just gave up on the turn, so button doesn't need to have a strong hand to sense weakness here and try to push us off.

i think keeping the lead on the turn for ~13 is the optimal line here.
i think check calling is worse than folding.

if we're beat, we're usually hearing from button right here. if we call and a blank falls on the river, we payoff even more than a lead that we fold.
if we're ahead and we call, we still lose a lot of the time since so many bluffable or draw-completing cards (assuming villain's on a draw) arrive on the river. any club, A, Q, T, 7. if there weren't so many dangerous river cards, it might make more sense to check-call to pick off a river bluff, but this board is often going to develop in a way that will make us face another river bet without really knowing wtf is going on in this hand.

We lost control of this pot by not overbetting the flop

True. I think it's pretty close between lead or check/fold at this point. Check-calling is really bad though.

I would have bet more on the flop. Sacrifice the extra buck or two. Either you take it down or you at least have better reason to check/fold on the turn if you still get called on the flop when the K hits the turn.

I would have bet more on the flop. This is the situation where a *full* pot-sized bet really *is* required, so bet anywhere from $8 to $10 on the flop.

If you don't do that, I still recommend leading the turn: if you give up here, the button is bound to bet ATC here. Now obviously he has some sort of hand to call the flop bet (unless he's a habitual floater... but it's a bad spot with the blinds left to act on the flop), but that doesn't mean that he now has a better hand than yours after the turn card. Lead for a little over half-pot on this turn. Obviously, this is risking *a lot * more chips, which is why that larger flop bet has been recommended by almost all the replies so far.

By checking the turn, you've left yourself up the creek without a paddle.

as played i would probably call here and re-evaluate the river...he could easily have a club draw, a nine, possibly a straight draw, there too many hands we can beat to throw it away, but not enough hands we can beat to justify raising

also, leading the turn is much better than checking

As stated the flop is a minimum pot bet.

For the turn I think a B/F is wayyyyyyy better that a C/C or C/F.