I know the mother is weird,but I think there's something fishy about the son.

yeah, its his fucked up crazy mom. She raised him to be an extension of herself and manipulates the poor thing. I mean imagine, if you spend so much time around one person and feel super close to them and see them one way...your brain just can't reconcile this new image/ fact that doesn't fit them. Its insane but we're able to convince ourselves we didn't see what we saw because its just so unbelievable.