pp against a maniac on a weak board

[WillyTrailer]

Party 5/10 hold'em. Button is super LAG with 63/27/4.65 vpip/pfr/pfaf.
CO is passive and surely on a flush draw.
anyone think i'm crazy against a guy with those numbers?

Party Poker 5/10 Hold'em (10 handed) converter

Preflop: Hero is MP2 with 7[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/diamond.gif[/img].
UTG calls, <font color="#666666">3 folds</font>, Hero calls, <font color="#666666">1 fold</font>, CO calls, <font color="#CC3333">Button raises</font>, <font color="#666666">1 fold</font>, BB calls, UTG calls, Hero calls, CO calls.

Flop: (10.40 SB) J[img]/images/graemlins/heart.gif[/img], J[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/diamond.gif[/img] <font color="#0000FF">(5 players)</font>
BB checks, UTG checks, <font color="#CC3333">Hero bets</font>, CO calls, <font color="#CC3333">Button raises</font>, BB folds, UTG folds, Hero calls, CO calls.

Turn: (8.20 BB) 3[img]/images/graemlins/spade.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, CO checks, <font color="#CC3333">Button bets</font>, <font color="#CC3333">Hero raises</font>, CO calls, <font color="#CC3333">Button 3-bets</font>, Hero calls, CO calls.

River: (17.20 BB) 9[img]/images/graemlins/heart.gif[/img] <font color="#0000FF">(3 players)</font>
Hero checks, CO checks, <font color="#CC3333">Button bets</font>, Hero calls, CO folds.

Final Pot: 19.20 BB