I don't know, the guy just doesn't seem to take well to the idea of being a cuckold. And even though he's a bit reckless, (Proof of that is that he buried himself with David, after revealing his feelings to Alice.) I don't think he'll tell all his neighbors, "I fucked my mother, stop anyone who wants to blackmail her, they can blackmail her with that!". A more plausible future, is that David stays with Alice, and Aaron stays with Sarah. After all, it seems that Uncle Peter will be away for a while. [Hopefully he'll stop for good.] So maybe Aaron can take a more leading role, since he seems to have quite a bit of potential, I don't think they'll look down on him by making him just a cuckold.