0.25/0.50 NL AJos facing some heat on the flop

[smutgremlin]

Opponent just sat down recently. Maybe at most played 15 hands. If I can recall, he's raised only once since he's sat down.

Party Poker - No Limit Hold'em Cash Game - $0.25/$0.50 Blinds - 6 Players - (LegoPoker Hand History Converter)

SB: $29.69
BB: $113.20
UTG: $57.26
MP: $32.56
CO: $45.68
Hero (BTN): $103.59

Preflop: Hero is dealt A[img]/images/graemlins/club.gif[/img] J[img]/images/graemlins/spade.gif[/img] (6 Players)
UTG folds, MP calls $0.50, CO calls $0.50, <font color="red">Hero raises to $3.00</font>, SB folds, BB calls $2.50, MP folds, CO calls $2.50

Flop: ($9.75) J[img]/images/graemlins/club.gif[/img] 2[img]/images/graemlins/club.gif[/img] 5[img]/images/graemlins/heart.gif[/img] (3 Players)
BB checks, <font color="red">CO bets $5.00</font>, <font color="red">Hero raises to $12.50</font>, BB folds, <font color="red">CO raises all-in to $42.68</font>, Hero folds

Pot Size: $64.93

Is there any way I'm calling this shove and why?

Thanks in advance.

-gremlin