PokerStars No-Limit Hold'em, $1.00 BB (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

MP2 ($112)
CO ($100)
Button ($155.80)
SB ($196.20)
Hero ($114.95)
UTG ($108.35)
UTG+1 ($118.30)
MP1 ($41.50)

Preflop: Hero is BB with 8, 7. CO posts a blind of $1.
4 folds, CO (poster) checks, 1 fold, SB completes, Hero checks.

Flop: ($3) 9, 6, 5 (3 players)
SB checks, Hero bets $2, CO calls $2, SB folds.

Turn: ($7) 5 (2 players)
Hero bets $6, CO calls $6.

River: ($19) Q (2 players)
Hero bets $13, CO raises to $26, Hero ...

I feel like I should 3-bet this river. I don't think he flopped a set or two pair or he would have likely raised on the flop with the flush draw out there, and QQ is extremely doubtful. So then the only hand I think he would have that beats me is Q5, and I think he calls a 3-bet with any 5.

Thoughts?