[bbartlog]

Is SB still in the hand? Did he check the turn? If you are very confident of your read on villain, then your equity here is good enough to call his bet - but there are obviously a lot of non-spade cards (any A 3 5 or 8 off the top of my head) that would also be scary on the river and might result in either an incorrect fold on your part or a scoop for villain.
Anyway, given full stacks or deeper for both you and villain, I think I fold, but if either your or villain had only $80 or so to start the hand I call.