[Closed] FL 0.5/1FR: 37s flopped flush

I do not know why I have called the river... is check fold to weak?

How would you go with this hand?

TTT

Known players:
[tg]Position_Stack:hands/vp$ip/RaisePreflop/AF/WTS/ORL/BBvsSteal/W$SD;Hero$57,60:///////;BB$24,50:537/13/8/1,8/36/27/80/56;UTG1$31,35:150/17/7/1,9/25/30/0/67;UTG2$32,70:140/14/10/1,7/32/25/-/50;MP3$23,50:126/14/8/0,9/50/57/-/70;CO$24,25:163/42/10/1,0/30/15/67/38;[/tg]
0,5/1 Fixed-Limit Hold'em (9 handed)
Hand recorder used for this poker hand: PokerStrategy Elephant 0.67 by www.pokerstrategy.com.

Preflop: Hero is SB with 3♦, 7♦
UTG1 calls, UTG2 calls, 2 folds, MP3 calls, CO calls, BU folds, Hero calls, BB checks.

Flop: (6,00 SB) K♦, 6♦, 8♦ (6 players)
Hero checks, BB checks, UTG1 bets, 2 folds, CO calls, Hero raises, BB folds, UTG1 calls, CO calls.

Turn: (6,00 BB) 6♠ (3 players)
Hero bets, UTG1 raises, CO calls, Hero calls.

River: (12,00 BB) 3♣ (3 players)
Hero bets, UTG1 raises, CO 3-bets, Hero calls, UTG1 calls.

Final Pot: 21,00 BB