Loving someone doesn’t mean u have to be living with them till the day they die.. That’s over-attachment and not very healthy (for parents or son/daughter) imo.
Obviously inlaws in their 60s/70s/80s need more help and looking after (I don’t mean financially cos a lot of them are living much more simply by then, mortgage prob already paid off etc) than those in their forties.
Also, I really can’t see how people in their forties need their kids around (unless they’re ill)?? Don’t they have jobs and their own social lives?? I’d find it a bit odd if ppl that age were so emotionally or physically dependent on having their sons around all the time..