6.5: KK with an A on the flop

[Kibby]

Do I fold this here? how was the flop bet?

PokerStars Tournament, Big Blind is t20 (8 handed) Converter on pregopoker.com

UTG (t1690)
UTG+1 (t1500)
MP1 (t1500)
MP2 (t3230)
Hero (t1490)
Button (t1470)
SB (t1120)
BB (t1500)

Preflop: Hero is in CO with K[img]/images/graemlins/spade.gif[/img] K[img]/images/graemlins/club.gif[/img]
<font color="gray">UTG folds</font>, <font color="gray">UTG+1 folds</font>, <font color="red">MP1 raises to t100</font>, <font color="gray">MP2 folds</font>, <font color="red">Hero raises to t360</font>, <font color="gray">Button folds</font>, <font color="gray">SB folds</font>, <font color="gray">BB folds</font>, MP1 calls t260

Flop: (t750) A[img]/images/graemlins/heart.gif[/img] 6[img]/images/graemlins/club.gif[/img] 5[img]/images/graemlins/diamond.gif[/img] (2 players)
MP1 checks, <font color="red">Hero bets t500</font>, MP1 calls t500

Turn: (t1750) J[img]/images/graemlins/spade.gif[/img] (2 players)
MP1 checks, Hero checks

River: (t1750) T[img]/images/graemlins/club.gif[/img] (2 players)
<font color="red">MP1 bets t640 (All-in)</font>, Hero ?