Villain is 20/15 over 210. Has rerasied me otf twice vs my cbet and hasn't 4bet. Flop sizing sucks? What to do on turn?

Cake Poker, $0.25/$0.50 No Limit Hold'em Cash, 5 Players
Poker Tools Powered By Holdem Manager - The Ultimate Poker Software Suite.

CO: $50.50 (101 bb)
BTN: $14.25 (28.5 bb)
Hero (SB): $54.35 (108.7 bb)
BB: $22.65 (45.3 bb)
MP: $101.39 (202.8 bb)

Preflop: Hero is SB with K K
MP folds, CO raises to $1.50, BTN folds, Hero raises to $4.50, BB folds, CO calls $3

Flop: ($9.50) A 9 5 (2 players)
Hero bets $4.75, CO calls $4.75

Turn: ($19) 7 (2 players)
Hero ???