This should have been an easy laydown....right?

PokerStars No-Limit Hold'em, $0.25 BB (9 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

saw flop|saw showdown

MP1 ($27)
MP2 ($17.70)
MP3 ($23.65)
CO ($5.70)
Button ($19.80)
SB ($22.90)
Hero ($40.25)
UTG ($25.55)
UTG+1 ($15.75)

Preflop: Hero is BB with 9, 9.
1 fold, UTG+1 raises to $0.75, MP1 calls $0.75, MP2 calls $0.75, MP3 calls $0.75, 2 folds, SB calls $0.65, Hero calls $0.50.

Flop: ($4.50) 9, J, K (6 players)
SB checks, Hero bets $2, UTG+1 raises to $8, MP1 calls $8, MP2 folds, MP3 folds, SB folds, Hero raises to $15, UTG+1 calls $7 (All-In), MP1 raises to $26.25, Hero calls $11.25.

Turn: ($72) 5 (3 players, 1 all-in)

River: ($72) A (3 players, 1 all-in)

Final Pot: $72
Main Pot: $49.50, between MP1, Hero and UTG+1. > Pot won by MP1 ($49.50).
Pot 2: $22.50, between MP1 and Hero. > Pot won by MP1 ($22.50).

Results in white below:
Hero has 9d 9s (three of a kind, nines).
UTG+1 has Ks Ad (two pair, aces and kings).
MP1 has Qc Tc (straight, ace high).
Outcome: MP1 wins $72.

[EDIT]
MP1 is 24.4/2.4 over 41 hands
UTG+1 is 26.5/16.6 over 30 hands

You MIGHT be able to fold this, but I doubt it. If you are behind to a set, you are drawing almost dead, but that is a small part of the range. Might be looking at AK, AA, KJ. If you are behind to a flopped str8, then you have 10 outs (40%) to draw out with two cards to come. I think I go broke here most times. Dead money makes it a call for sure, even on the last bet.

If you are going to lead on the flop, lead more than 1/2 pot. Lead 2/3 or more......

even with all the cards face up, you still should have gotten all in. You got all in with 30% equity in a 75 pot. This is fine. Don't even think about every laying down sets in raised pots at 25nl.

You can't put someone you've played 40 hands with on exactly QT/JJ/KK

Don't post results

With 3 people to act behind you (including the pf raiser), check/raise. If UTG cbets and gets callers you're trapping money in the pot. If you're going to donk bet the flop, bet more, $3-4.

Thanks for the replies, put it in perspective since I hadn't run it through pokerstove yet.

I tossed up about adding the results but figured the thread title gave it away anyway so I may as well

Not sure why I bet the flop so small tbh, normal bet size should have been $3-4 so that was a weird one that I hadn't noticed.

After MP1's all in re-raise I knew what he had but then was looking at about 5.5:1 odds to call hoping for the board to pair which I guess is the main thing and the one that had me questioning my play but now I am thinking over it with the replies here I'm fairly happy I did the right thing I thing.

Thanks guys, and will try to keep results out and thread titles spoiler free again from now on

gotta make this play every time, otherwise you are missing a lot of value on sets. Some poker hands you are 'destined' to lose money on :/