I think personal the flop call from the Villian was questionable, and he'd made a lot of weird min raises in EP, pot steal attempts etc but was yet to show anything down so this was my first hand against him.

PokerStars No-Limit Hold'em, 1.5 Tournament, 15/30 Blinds (8 handed) - PokerStars Converter Tool from FlopTurnRiver.com

saw flop | saw showdown

MP1 (t1825)
MP2 (t1490)
CO (t1245)
Hero (Button) (t3110)
SB (t1380)
BB (t1360)
UTG (t1470)
UTG+1 (t1620)

Hero's M: 69.11

Preflop: Hero is Button with J, K
1 fold, UTG+1 bets t60, 2 folds, CO calls t60, Hero calls t60, 1 fold, BB calls t30

Flop: (t255) 5, J, 2 (4 players)
BB checks, UTG+1 bets t30, CO calls t30, Hero raises to t288, BB calls t288, 1 fold, CO calls t258

Turn: (t1149) 7 (3 players)
BB checks, CO checks, Hero bets t1149, BB calls t1012 (All-In), CO calls t897 (All-In)

River: (t4070) 9 (3 players, 2 all-in)

Total pot: t4070

Results below:
Hero had J, K (one pair, Jacks).
BB had 3, A (flush, Ace high).
CO had 4, 3 (high card, Jack).
Outcome: BB won t4070

You overplayed your top pair. No reason to bet on the turn...its checked to you, you've got one street of value. Now the flush is out and your multiway. What were you hoping was going to call a pot sized bet that is worse that your hand?