It doesn’t take a Master’s Degree, not even a High School Diploma to see something ‘shady’ about In laws swallowing the spouse of their child.
Where that spouse’s family is cut out so In Laws replace them, a warning bell should go off.
Sure if X is an orphan or totally severed from their family fine. Fill the void. But don’t make the void. Don’t leave out Mommy & Daddy & Brother so as to make sure that this person is isolated.
This person who once had a mother/father/siblings now has no one but the In Laws.
In the case of Dan and Candy, if he cheated on her, what could she do?
Divorce her entire family.
No more Mommy In Law making Parties and Granny In Law being the baby sitter, and Uncle In Law loaning her a car. All GONE.
So if Dan cheats, Candy has to live with it unless Dan wants her gone, and she is swept out.
Losing not just Dan, but her whole ‘family’, her whole ‘world’