She does not realize, friends tell her.

Olivia waits outside her house for roughly 10 minutes, the few cars that pass by all honk at her, the drivers staring in shock, she just waves at them. Finally her friends arrive, also staring at her in shock, before asking why she isn't wearing anything. Olivia freaks out, and puts one of the outfits from her bag. Down to one spare outfit for the trip now.

Her friends tease her about how she could have possibly left the house naked and not noticed, all the way onto the plane, luckily security gave them no trouble.