5NL FR

Hero is UTG+1 with 80BB's
MP has 100BB's
Button has 30BB's


I am UTG+1 with (KdKh)

I raise to 4BB's
MP- calls. He is a maniac who is playing ATC. Running 40/30 for 200 hands.
Button calls- running 30/8 for 100 hands

Flop- (13.5 BB in pot)
Ac 6c As

MP's range is literally ATC. He has been bluffing frequently (on nitty table) and showing the bluffs.
Buttons range based on last 100 hands is {A7o+, A2s+, K9s+, KJo+, 88+}

If I bet out and MP folds, button calls I could change his range to {A7o+, A2s+, Kcxc}
If I bet out and MP raises or jams flop then I am probably drawing almost dead.
I really don't give any respect to MP if he raises me here.. I'm fine with getting it allin vs his range in this position.

Would it be better to check/raise here? Find out if someone really has an ace... or to bet out and fold to resistance?