NL10 - 5x Pot Overbet Shove on the River and All I've Got is a Boat!?!

[yasher]

Alright folks, here we go again. Villain's tight. I've seen him show down like three hands. The only two notables were an AQ hand where he flopped 2pair and bet every street OOP and a hand where he limped Q6s OTB , flopped two pair on a somewhat wet board and bet the flop/turn in position but checked the river behind on a board that really hadn't improved. He's at 26/5/1 over ~50 hands.

Poker Stars - No Limit Hold'em Cash Game - $0.05/$0.10 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $11.30
BB: $1.40
UTG: $10.60
MP: $11.10
CO: $9.85
Hero (BTN): $12.35

Preflop: Hero is dealt 5[img]/images/graemlins/spade.gif[/img] 5 (6 Players)
UTG folds, MP calls $0.10, CO folds, <font color="red">Hero raises to $0.50</font>, SB calls $0.45, BB calls $0.40, MP calls $0.40

Flop: ($2) 7[img]/images/graemlins/heart.gif[/img] 7 9 (4 Players)
SB checks, BB checks, MP checks, Hero checks

Turn: ($2) 2 (4 Players)
SB checks, BB checks, MP checks, Hero checks

River: ($2) 5 (4 Players)
<font color="red">SB bets all-in for $10.80</font>, BB calls all-in for $0.90, MP calls all-in for $10.60, Hero throws up.

What on earth. Reasonably, I beat what, 22 and the naked A... and there are already a caller! Someone's gotta have 77, 99, 79, 72, 68... right?

This has gotta be a fold, yeah?