Poor Dad, NTR'ed by a kid of around his reincarnated 40-year old elementary school kid wife's age...
This makes for some nice worldbuilding and drama, to be fair. This girl isn't just Takae. She's Shiraishi Marika, something that our good ol' family (especially Dad) will have to deal with.
For now... fck off, appropriately aged pipsqueak. The apple of your eye is already married 🍜💢