NL100: KK oop wtf is going on?

[VinniePaz]

No-Limit Hold'em, $1.00 BB (6 handed) - Hold'em Manager Converter Tool from FlopTurnRiver.com

MP ($95.90)
Hero (CO) ($108.30)
Button ($100)
SB ($108.50)
BB ($93.20)
UTG ($100)

Preflop: Hero is CO with :ks, :kc
2 folds, Hero raises $4, Button calls $4, 2 folds

Flop: ($9.50) :3c, :9s, :2c (2 players)
Hero bets $7, Button raises $19, Hero raises $45, Button calls $26

Turn: ($99.50) :jc (2 players)
Hero checks, Button bets $51 (All-In), Hero folds

Total pot: $99.50

Villain: 19/15/4 3bet, 2.9 aggr.