Rivered flush in huge pot bet or CR

[ISF]

Villan had been playing pretty aggressively try to cr the field, or just bet out? As I had backdoored the flush I didnt think it would be that scary.
Party Poker 10/20 Hold'em (6 max, 6 handed) converter

Preflop: Hero is MP with K[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/diamond.gif[/img].
UTG calls, <font color="#CC3333">Hero raises</font>, <font color="#666666">1 fold</font>, <font color="#CC3333">Button 3-bets</font>, SB calls, <font color="#666666">1 fold</font>, UTG calls, Hero calls.

Flop: (13 SB) 3[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/club.gif[/img], 5[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, <font color="#CC3333">UTG bets</font>, Hero calls, <font color="#CC3333">Button raises</font>, SB calls, UTG calls, Hero calls.

Turn: (10.50 BB) 9[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, UTG checks, Hero checks, <font color="#CC3333">Button bets</font>, SB calls, UTG calls, Hero calls.

River: (14.50 BB) 2[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(4 players)</font>
SB checks, UTG checks, Hero checks, Button checks.

Final Pot: 14.50 BB