I isolated one player on CO, he folded but BB calls. On the flop I have flush draw (K kicker), and two overcards, he donks with little bit smaller than 1/2 bet, I called, on the Turn he continues with bigger bet, I have to fold.

We have history, so here are some of his stats:

iPoker - €0.02 NL (6 max) - Holdem - 6 players
Hand converted by PokerTracker 4: http://www.pokertracker.com

SB: 35 BB
BB: 139 BB
UTG: 101.5 BB
MP: 89 BB
Hero (CO): 118.5 BB
BTN: 124.5 BB

SB posts SB 0.5 BB, BB posts BB 1 BB

Pre Flop: (pot: 1.5 BB) Hero has Kc Jc
fold, MP calls 1 BB, Hero raises to 4 BB, fold, fold, BB calls 3 BB, fold

Flop : (9.5 BB, 2 players) 9h 5c 7c
BB bets 4 BB, Hero calls 4 BB

Turn : (17.5 BB, 2 players) 2h
BB bets 11 BB, fold

BB wins 16.5 BB