Villain is 37/10/2.57 No river aggression.

The only big pot I saw him in was with me and another guy where he limped with 34o in LP and I checked BB w/34s (spades) we both flopped the bottom straight with the 3rd guy flopping a set. I turned the flush but check called down. Villain just kept betting and betting whilst I just kept calling. Should have raised and got it all in but I was afraid of higher flush but thats another hand.

Anyway, when he push the river I found it hard to believe he had an ace but more like a set or a weird straight hand. What do you think? Fold this river push or call the donk down?

http://www.pokerhand.org/?1005108