If you have enough hands on villain to know he's super passive and only comes alive with hands better than your over-pair, folding isn't a bad idea. 3betting the flop and folding to a 4bet works too. One thing I've learned (and learned the hard way) is that at <25nl they almost always have it (unless you have super reads or villain is a aggro fish). Don't think they're playing back at you, they aren't.