TPTK + nut flush draw - Call this gross overbet?

[whitelime]

I've never played with this guy so I have no reads. Is this a standard call?

Party Poker No-Limit Hold'em, $ BB (6 max, 5 handed) converter

Hero ($608.25)
BB ($698.25)
UTG ($782.35)
MP ($546)
Button ($233.45)

Preflop: Hero is SB with A[img]/images/graemlins/club.gif[/img], K[img]/images/graemlins/spade.gif[/img]. Hero posts a blind of $3.
<font color="#666666">1 fold</font>, <font color="#CC3333">MP raises to $25</font>, <font color="#666666">1 fold</font>, Hero (poster) calls $22, <font color="#666666">1 fold</font>.

Flop: ($56) 8[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/spade.gif[/img], 4[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, MP calls $521 (All-In), Hero calls $521.

Turn: ($1098) 2[img]/images/graemlins/club.gif[/img] <font color="#0000FF">(2 players, 1 all-in)</font>

River: ($1098) Q[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players, 1 all-in)</font>

Final Pot: $1098

Results in white below: <font color="#FFFFFF">
Hero has Ac Ks (flush, ace high).
MP has Ad Ah (three of a kind, aces).
Outcome: Hero wins $1098. </font>