I would babysit a 6 year old boy who was still in diapers full time and would have no issue changing his diapers for him either.
I would love to change a 6 year old boys diaper and babysit him and even put him to bed in a baby bed and feed him a bottle of milk and give him a pacifier.
6 year old boys should be in diapers full time and if it were my own son I would also keep him in diapers to keep him my little baby for as long as I could.
Below is a link to a full collection of pictures of an 8 year old boy named Tommy who was made to wear plastic backed pampers diapers by his dad and treated like a toddler.
I wish that were me getting that treatment as I would enjoy it.
8 year old diaper boy Tommy wearing plastic pampers full collection of pictures