If he has 2x, then I'd hate to see what he has with it, and you need to be 3-betting a heck of allot wider than AJs, if he has 33 or AA, surely he is betting the river after we check behind on the turn. Maybe he hit his flush and doesn't think we have an A. Anyways, I can't see how you cannot call. If he shows up with a better house or quads, we say wafi, and move along.