My mom thinks I'm going camping with the guys.
4 seconds sound clip from the Back to the Future movie soundboard.
You can hear this line at 00:10:07 in the Blu-ray version of the movie.
Quote context
[...]
- Does your mom know? About tomorrow night?
- My mom thinks I'm going camping with the guys.
- I mean, look, I think the woman was born a nun.
- She's just trying to keep you respectable.
- Well, she's not doing a very good job.
[...]