It's "under the influence" 8th season, kimmy and D.J. Get invited to a party. But when guys show up with beer, the guys get kicked out.... But not before kimmy gets drunk. After that kimmy spends the night in D.J.'s cama after she wakes up and makes up what she thinks really happened. But being so so off. (Being the sunshine of the party, so mature and well mannered, while D.J.'s sitting on "reject row" with nerds as kimmy says) after being told how D.J.'s mom died when she was little kimmy believes her.
That episode is called Under the Influence, and is from Season 8. In it, Kimmy gets drunk at a fraternity party and DJ refuses to let her drive, and Kimmy gets mad at her. Later, Kimmy sobers up, changes her attitude and apologizes when DJ explains that years ago, it was a drunk driver who caused the car accident that killed Pam Katsopolis-Tanner (the girls’ mother, Jesse’s older sister and Danny’s wife).
DJ: My mom died because of a drunk driver. I wasn’t gonna lose my best friend the same way.