AQo 100NL party deepstacks

[Morrek]

Button is 55/8 borderline maniac with 35% WTSD. He chases any draw and calls down with pretty much any piece, and has been on a huge rush. For example maybe 30-something hands ago he called potbets on flop+turn with A2o on 45x flop and x turn, catching an A on the river and winning a decent pot. Then this happened:

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

SB ($105.90)
BB ($102.30)
Hero ($270.80)
MP ($95.90)
Button ($648.75)

Preflop: Hero is UTG with A[img]/images/graemlins/spade.gif[/img], Q[img]/images/graemlins/diamond.gif[/img]. SB posts a blind of $0.50.
<font color="#CC3333">Hero raises to $4</font>, <font color="#666666">1 fold</font>, Button calls $4, <font color="#666666">2 folds</font>.

Flop: ($9.50) 4[img]/images/graemlins/spade.gif[/img], A[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $9</font>, Button calls $9.

Turn: ($27.50) J[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(2 players)</font>
<font color="#CC3333">Hero bets $20</font>, Button calls $20.

River: ($67.50) K[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(2 players)</font>
Hero checks, <font color="#CC3333">Button bets $80</font>, Hero ??

Final Pot: $147.50


Bet more on turn? Block river? I haven't seen him bet this big on the river before, I figured check/call would be cheapest but I might've been wrong. Any ideas?