Bit of background - DS (5) not fully continent - being treated for constipation and it isn't working. School treated him horrifically, new school now.
One thing I have noticed it he likes to pretend he is a baby - it got so much worse, or really started, when school wanted him in pull ups only.
I am potty training his younger brother (2) who has had a few accidents on the patio - potty has been outside in the good weather. DS1 (5) has taken to weeing now on the patio - even if DS2 is using his potty! Just now DS2 had an accident on the carpet, so DS1 just wee-d right next to it.
When I have to change his soiled clothes he makes baby noises, or shouts at his brother that he is a baby, or shouts out "baby baby baby nappies nappies"... things like that.