I have never played with this guy before, him being the preflop raiser his check calling my bets had me a little confused...

PokerStars No-Limit Hold'em, $1.00 BB (6 handed) from (Format: Bet The Pot)

SB ($223.40)
BB ($168.40)
UTG ($115.85)
MP ($175.25)
CO ($154.60)
Hero ($119.45)

Preflop: Hero is Button with , .
2 folds, CO raises to $4, Hero calls $4, 2 folds.

Flop: ($9.50) , , (2 players)
CO checks, Hero bets $7, CO calls $7.

Turn: ($23.50) (2 players)
CO checks, Hero bets $16, CO calls $16.

River: ($55.50) (2 players)
CO bets $17, Hero ?

I mean I am getting over 4 to 1, but can he have that he is check calling me with on the flop and turn that then blocking bets that river that I beat? I mean like the only hand he has here I bet is 67 or maybe 44.

I muck this.