villian was 76/27/0.88 through 80 hands. I had pushed him off of several hands earlier but this is the first time he played a hand this hard. What is the best line here?

PokerStars No-Limit Hold'em, $0.25 BB (8 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP2 ($38.65)
CO ($26.50)
Button ($4.15)
SB ($27.85)
BB ($47.90)
UTG ($4)
Hero ($47.90)
MP1 ($17.30)

Preflop: Hero is UTG+1 with K, K.
UTG calls $0.25, Hero raises to $1, 5 folds, BB calls $0.75, UTG calls $0.75.

Flop: ($3.10) 6, 5, 5 (3 players)
BB bets $0.5, UTG folds, Hero raises to $3, BB calls $2.50.

Turn: ($9.10) 7 (2 players)
BB bets $19, Hero ??????