We have no issue with adults who have authority over their own children.
When you look at it, there is a fairly significant differential in the cost of the oil and it makes a big difference. If there was a vendor that had access to that reduced cost, we would give it serious consideration.
Theoretically, an individual of any age could be on private property and could be consuming or possessing alcohol. It is perfectly legal.
That one was particularly egregious in terms of the parents' level of involvement in putting the party on.