I guess the fact that he re-raised me PF and then checked on the flop should have set off some warning bells in my head but I thought he might have been afraid of the A.
PokerStars No-Limit Hold'em, $0.05 BB (9 handed)
internettexasholdem.com
CO ($2.77)
Button ($2.45)
SB ($7.21)
BB ($2.67)
UTG ($11.43)
Hero ($5.89)
MP1 ($10.19)
MP2 ($2.62)
MP3 ($5.61)
Preflop: Hero is UTG+1 with

,

. CO posts a blind of $0.05.
1 fold,
Hero raises to $0.15,
2 folds, MP3 calls $0.15,
3 folds,
BB raises to $0.45, Hero calls $0.30, MP3 calls $0.30.
Flop: ($1.42)

,

,
(3 players)
BB checks,
Hero bets $0.75, MP3 folds,
BB raises to $2.22, Hero calls $1.47.
Turn: ($5.86)
(2 players)
River: ($5.86)
(2 players)
Final Pot: $5.86
Results in white below:
BB has Ah As (three of a kind, aces).
Hero has Ac Kd (one pair, aces).
Outcome: BB wins $5.86.