Great, wild, 20/40. Lots of dorks and one good prop.

I raise AKo utg and get 5 callers including the BB.

A63 I have no spade.

I bet, Jerry the prop calls, terrible button calls, loose BB calls.

2

BB checks, I bet, call, call, BB now c/r and I fold.

You're getting 12:1 so you need to figure out how many outs you have on average. How often are you drawing dead? It depends on how BB plays his flush draws. Would he put more action in on the flop? I would, it's a perfect spot to c/r the field for value with spades. Would he play a set this way? Against either hand, you're dead, but sometimes he is full of it, sometimes he's semibluffing with Ax with the x of spades (or 6x with the 6s), and sometimes he has two pair. Against A2 and A3 you have enough outs to call getting 12:1 and hope to improve, and against lower two pair you have even more. But it's up to you and your read to calculate how often you have outs and how often you're dead. I think in the heat of the moment I would call and fold to a spade river, call any A, 2, 3, 6 or K river, and soul read if like the 9h pops off.

Intuitively this seems like a good fold, but I'm too lazy to do the math right now. The good prop really shouldn't be flat calling this flop with anything other than a spade draw. Even for an idiot, BB's check-raise should at least be bigger than one pair. Even if no one has a made flush, chances are huge that someone has at least one spade, which cuts into your two pair outs. Finally, you aren't closing the action and there's a good chance of someone popping it behind you (the prop in particular).

Would you also have folded if the BB had donked this turn? Because IMO that's how more than half of the bad players in that game would actually play a flush or a straight. If your worried about players behind you, the prop almost certainly wouldn't play a flush draw/flush or a hand that has you beat this way. While I may not love my hand here, I don't think I'm ever folding to this action and am typically very showdown bound in these spots against these sorts of players.

I don't think it is very likely at all that either player behind him was slow-playing this turn hoping for a BB CR or a heroic river play... especially the prop.

I wasn't thinking a flop slow-play so much as a hand that got there on the turn (straight or flush).

I think its a fine fold since you're drawing dead so so often.

fold is 100% standard here with so many f-ing ppl and that turn card