Full Tilt, $0.10/$0.25 No Limit Hold'em Cash, Rush, 6 Players
MP: $14.73 (58.9 bb) unknown
CO: $28.06 (112.2 bb) unknown
BTN: $24.19 (96.8 bb) reg 25/18/5 1.7k h folds quite a bit to 3bets in general
SB: $23.28 (93.1 bb)
Hero (BB): $84.84 (339.4 bb)
UTG: $33.65 (134.6 bb)
Preflop: Hero is BB with A
A
UTG folds, MP raises to $0.50, CO calls $0.50, BTN calls $0.50, SB folds, Hero raises to $3, MP calls $2.50, CO calls $2.50, BTN calls $2.50
Flop: ($12.10) 5 2 9 (4 players)
Hero bets $5, MP folds, CO raises to $25.06 and is all-in, BTN calls $21.19 and is all-in, Hero 
What would be your play in such spot?
is really bad here because it means he can't be shipping the nut flush draw. You pretty much always see a set here , if it's 3 way with regs.