It's bad to leave without telling anyone.
Jenna has been at a party for three hours and is getting tired, but knows her friends will try to convince her to stay.
Jenna wants to go home and sleep.
As Jenna walks out the door, she tells her friends she had a great time, but she feels really tired.
Jenna sneaks out the back door without talking to her friends.
Jenna's friends only have time to wave goodbye before she's on the sidewalk walking home.
Jenna goes home and sleeps while her friends panic about her going missing.