Yes, 12 year olds can wear diapers.
You let him or her wear diapers. You can't force the 6 year old to do something they don't want to do.
Because they are not potty trained
It's not common, as most women will want to be more discreet about it.
Yes they should still be in diapers at this age
Well just tell him he needs to wear diapers again.
Unless he has any disabilities or conditions - no.
Yes. It is generally used if a person has a disorder.
I am 19 and I wear diapers 24/7 for medical reasons. So yes :3
12 year old should not be wearing diapers unless they have a disability or a developmental condition that doesn't allow them to control bodily functions.
never too old
If he likes the design and the colors then let him wear them. Plus if wants to wear a dress let him.