Parents who constantly go out drinking every other day or every weekend. Their friends most likely also party parents or partiers, gather 'round and drink until the morning hours. Party parents most likely have a well paying job, nice house, and definitely kids. Some party parents don't pay much attention to their sons and daughters because the would rather go drinking with their friends.

The people at a party who perform the tasks a parent would, but instead of young children, there are inebriated guests. eg., cleaning up puke, hydrating, arranging transportation, finding place for everyone to sleep, generally maintaining happiness/health.