Weird Ace King hand confused

[DiabloVt7]

Villain is 51/6 over 95 hands with ag factor of 2.5

Full Tilt No-Limit Hold'em, $1 BB (6 handed) Hand History Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver Cards)

BB ($98.50)
UTG ($64)
MP ($79.85)
Hero ($139.70)
Button ($105.70)
SB ($107.55)

Preflop: Hero is CO with , .
[color=#666666]2 folds</font>, [color=#CC3333]Hero raises to $3.5</font>, [color=#666666]1 fold</font>, SB calls $3, [color=#666666]1 fold</font>.

Flop: ($8) , , [color=#0000FF](2 players)</font>
SB checks, Hero checks.

Turn: ($8) [color=#0000FF](2 players)</font>
[color=#CC3333]SB bets $1</font>, Hero calls $1.

River: ($10) [color=#0000FF](2 players)</font>
[color=#CC3333]SB bets $5</font>

what should heros action be? what should heros action be if villain reraises us after we raise river.