NL 400 did I donk this up???

[RikaKazak]

UTG was a SUPER DONK, raising 5,To and calling big bets with it, not sure why he folded this time, maybe cause of my stack. I have reraised him twice and both times called preflop and he folded to my flop c-bet heads up in the past 45 hands. The 2nd player seemed like a typical 31/9 player that probably lost a little bit but not horribly, what do you think of the flop decision to call or fold to his raise????

Party Poker No-Limit Hold'em, $ BB (6 max, 4 handed) FTR converter on zerodivide.cx

BB ($343.65)
UTG ($1825.52)
Button ($779.90)
Hero ($726.14)

Preflop: Hero is SB with K[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img]. Hero posts a blind of $2.
UTG raises to $15</font>, Button calls $15, Hero (poster) raises to $58</font>, 1 fold</font>, UTG folds, Button calls $45.

Flop: ($139) 4[img]/images/graemlins/club.gif[/img], 6[img]/images/graemlins/diamond.gif[/img], 8[img]/images/graemlins/heart.gif[/img] (2 players)</font>
\Hero bets $100</font>, Button calls $719.90 (All-In),