Not based on their age but their activities/judgement. It was an oblique reference to the idiom "no adults in the room". https://idioms.thefreedictionary.com/

Not based on their age but their activities/judgement. It was an oblique reference to the idiom "no adults in the room". https://idioms.thefreedictionary.com/adults+in+the+room https://idioms.thefreedictionary.com/adults+in+the+room