WA/WB facing obv aggression

[Chopper]

just wanted to see what is standard here. no reads on opponent...at least i havent noticed anything odd, yet.

Absolute Poker No-Limit Hold'em, $0.25 BB (6 handed) Absolute Poker Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

CO ($24.65)
Button ($64.60)
SB ($29.89)
BB ($69.28)
UTG ($9.65)
Hero ($24.10)

Preflop: Hero is MP with A, K.
UTG calls $0.25, Hero raises to $1, 1 fold, Button calls $1, 2 folds, UTG calls $0.75.

Flop: ($3.35) A, 9, 6 (3 players)
UTG bets $1.25, Hero raises to $4, Button folds, UTG raises to $8.65, Hero ??

we are either WA/WB here. is villain deep enough to be taken seriously? i just dont like the limp/call, bet/push line much w/ AK. smells like 2pr or set.

[Warpe]

Once you've raised the flop it's an easy call. I'd call if he led with a shove, too, but that might be me disrespecting the stakes.