5/5 live turn the absolute nuts but OOP

5/5 live with 3k

We are doing $10 btn straddles with some people doing blind raise to $20 in sb. Going multiway to flops every hand. All bad players/whales and 2 pros.

Hero in MP with AKT9 with nut spades no clubs.

Sb $20 blind, bb $30 blind, 3 calls, hero call in LP, BTN $200, 4 of us call.

Flop ($1050) AK3cc
Checks to btn who pots, folds to hero who calls.

Btn is a fish. Last week he called my all in on the flop for $500 into $1000 with 2 players left to act on an A98r board with KTT6 1 bdfd and hit his gutter against my AAXX. I also had a hand the same week I had AKKX on QT94ss, river 8. He called my raise on turn and folded to my river jam when he had JJ8X. Said he hated that he folded (a whale showed he had the other 2 JJ he folded so I showed). He does weird stuff all the time. Overplays bad hands. Usually not for thousands though. I've also seen him run weird bluffs. Hard to figure him out because he doesn't make sense half the time. He also cbets any A high flop as PFR whether we are heads up or 6 ways to flop.

I think flop call is fine based on these things. Planning on probably just GII on clean turns if I check and he bets.

Turn ($3150) Ax
Hero check, V check

River Jx
Hero?

I have $1600ish behind. Do we rip it or check and hope he stabs at it? I feel like he should have a lot more bluffs than value hands here. Not sure what I get called by. He might fold his straights and bad aces at this point. But he might try to push me off with his no showdown hands like T987 and such. If I check and he checks back we so much value though.