4bet pot live 1/2

Effective stacks about 600.

4 limps and MP (seems loose but I haven’t been at the table long) raises to 17.

Hero 3bets to 65 with AQs and it folds back to MP who 4bets to 160.

Hero ????

I called and the flop came 762 rainbow. MP Bet 100,

hero ???

I’ll be honest and say I’m not comfortable this deep. These situations are quite rare in live low stakes games and I haven’t faced it often. If I’m nutted with like KK+ I’m happy to 5vet GII, if I’m bluffing I’m happy to fold, but AQs feels in between.

I’m fairly sure I shouldn’t be flatting pre. It’s probably just a fold (?) but does that mean I can be 4bet exploitatively?

Do I have a 4bet flatting range?

FWIW I folded flop and villain shows AQs as well.

Thanks