Gotta disagree with that. Despite my inner 14 year old boy desire to give this kid a high five, the 20 year old female is supposed to be the adult and should know better. She was entrusted with his care by his parents and even if the whole thing was the boys idea and he begged and begged (which my inner 14 year old boy can relate to), she is supposed to diffuse the situation and rebuff his advances.
How did a 20-yo girl buy alchohol to ply him with in the first place?
Would that not be ... illegal? Except in LA, I think - not sure.