Q7s flops a flush!!!

Is there a better river line. Should I call this bet? He is 42/9/2.75 after 45 hands.

Party Poker No-Limit Hold'em, $ Hero (8 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

SB ($21.45)
Hero ($104.75)
UTG ($170.11)
UTG+1 ($20.27)
MP1 ($118.80)
MP2 ($84.30)
CO ($49.05)
Button ($57.15)

Preflop: Hero is BB with 7http://www.flopturnriver.com/phpBB2/...iles/spade.gif, Qhttp://www.flopturnriver.com/phpBB2/...iles/spade.gif. SB posts a blind of $0.50.
UTG calls $1, 3 folds, CO calls $1, Button calls $1, 1 fold, Hero checks.

Flop: ($4.50) Ahttp://www.flopturnriver.com/phpBB2/...iles/spade.gif, 5http://www.flopturnriver.com/phpBB2/...iles/spade.gif, Thttp://www.flopturnriver.com/phpBB2/...iles/spade.gif (4 players)
Hero bets $3, UTG folds, CO calls $3, Button folds.

Turn: ($10.50) 8http://www.flopturnriver.com/phpBB2/...es/diamond.gif (2 players)
Hero bets $7, CO calls $7.

River: ($24.50) 3http://www.flopturnriver.com/phpBB2/...iles/spade.gif (2 players)
Hero checks, CO calls $38.05 (All-In), Hero

if he is that bad he is probably pushing almost any spade or he could be bluffing since you checked to him when the flush hit.

I think I'd like to take my chances here with this opponent.