Villain has AJss often here as it's really the only combo that makes any sense that beats us - villain pots flop 3-way, checks the joint worst card in the deck on the turn and then he wants to play for stacks when you look pretty nutted with that sizing (not a fan of river sizing btw).

This would only be a fold against the world's biggest nit though - we're getting such good pot odds and there's always a chance that this is just a terribly played 99, aces, set or bluff.