Gilmore Girls: Season 1, Episode 9

1 - 9: Rory's Dance

Chilton hosts a dance which Rory and Dean attend, confirming that they are "boyfriend-girlfriend". Emily sleeps over at Lorelai's the night of the dance to take care of Lorelai's injured back and to see Rory off. Rory and Dean fall asleep accidentally, causing Rory to arrive home at 5 a.m., which pushes Emily to think they had sex. Thus erupts another blow-up between Lorelai and her mother.