In religiously-themed 'Choose Your Own Adventure' books, a lack of adult supervision almost exclusively leads to becoming a teenage prostitute and having a crack pipe explode in your face. Fortunately for us all I haven't written any of those yet, so poor parenting creates Barely Legal instead.
Somewhere between a reference to the members age, practices and sexual preferences, the name applies to a household who've turned their various interests (from 'sitting around naked playing NES games' to 'living at the office and being accused of having an affair') into enough money to let them do nothing but have sex in the hot tub and have parties that disturb the peace for the next thousand years.