The key to faking out the parents is the clammy hands. It's a good non-specific symptom. I'm a big believer in it.
9 seconds sound clip from the Ferris Bueller's Day Off movie soundboard.
You can hear this line at 00:04:03 in the Blu-ray version of the movie.
Quote context
[...]
- Incredible. One of the worst performances of my career, and they never doubted it for a second.
- How could I possibly be expected to handle school on a day like this?
- This is my ninth sick day this semester. It's getting pretty tough coming up with new illnesses.
- If I go for 10, I'm probably gonna have to barf up a lung. So I better make this one count.
- You fake a stomach cramp, and when you're bent over, moaning and wailing, you lick your palms.
- It's a little childish and stupid, but then, so is high school.
- Life moves pretty fast. If you don't stop and look around once in a while, you could miss it.
[...]