Flush draw and overcard, check and call flop?

[Bill Lumberg]

Pre-Flop: Hero is BB with K [img]/images/graemlins/diamond.gif[/img] 4 [img]/images/graemlins/diamond.gif[/img]
3 folds, MP calls, MP+1 calls, 1 fold, cutoff calls, 2 folds, Hero checks.

Flop: (4.5 SB) J [img]/images/graemlins/diamond.gif[/img] 2 [img]/images/graemlins/diamond.gif[/img] 6 [img]/images/graemlins/club.gif[/img]
Hero checks, MP bets, MP+1 folds, cutoff folds, Hero calls.

Turn: (3.25 BB) 3 [img]/images/graemlins/heart.gif[/img]
Hero checks, MP checks.

River: (3.25 BB) K [img]/images/graemlins/spade.gif[/img]
Hero bets, MP folds.