200nl: Not sure what to do with AA vs fish and nit

[Mr_Donktastic]

Full Tilt Poker - No Limit Hold'em Cash Game - $1/$2 Blinds - 9 Players - (LegoPoker Hand History Converter)

SB: $236.80
BB: $216.85
UTG: $200.00
UTG+1: $209.95
Hero (MP1): $237.80
MP2: $276.05
MP3: $195.00
CO: $200.00
BTN: $209.95

CO posts $2.00
Preflop: Hero is dealt A[img]/images/graemlins/diamond.gif[/img] A[img]/images/graemlins/club.gif[/img] (9 Players)
2 folds, <font color="red">Hero raises to $9.00</font>, 2 folds, CO calls $7.00, 2 folds, BB calls $7.00

Flop: ($28) 7[img]/images/graemlins/diamond.gif[/img] 9[img]/images/graemlins/diamond.gif[/img] 2[img]/images/graemlins/spade.gif[/img] (3 Players)
<font color="red">BB bets $28.00</font>, Hero calls $28.00, <font color="red">CO raises to $70.00</font>, BB calls $42.00, Hero ????

BB is an super passive fish, CO is a total nit.

I've been playing like 25/19 but usually play 15/10.

Hero folds?