^ My read on the Amanes has been that they are completely and absolutely meant to be a thing, but it is not a positive thing even in-universe that they are meant to be a thing, rather that their minds are warped by their wish, driving them to love each other a little too much, and it being a case where trying to pull them apart would do more harm than good at this point...
Just because... wishes causing problems is kind of a general theme for this franchise, and even the most inconspicious wishes can lead to some bizarre consequences.