river screwplay

CO is 43/3/0.8
Button is 75/25 with a river AF of 2.8, but flop and turn both < 1

Party Poker 3/6 (6max, 6handed)

Preflop: Hero is MP with K[img]/images/graemlins/diamond.gif[/img], Q[img]/images/graemlins/heart.gif[/img].
1 fold, Hero raises, CO calls, Button calls, 2 folds.

Flop: A[img]/images/graemlins/heart.gif[/img] T[img]/images/graemlins/club.gif[/img] 3[img]/images/graemlins/spade.gif[/img]
Hero bets, CO folds, Button calls.

Turn: J[img]/images/graemlins/diamond.gif[/img]
Hero bets, Button calls.

River: 7[img]/images/graemlins/club.gif[/img]
Hero checks...

this seems standard given his river AF, unless i think the ace on board will discourage bets from his smaller pairs.
bonus question: is this a spot where i should give up on the flop, or do i have to call a bet anyways with the possibility of 10 outs?