I'm going to deflate a tire
Why would you deflate someone's tire?
I've heard it's fun to do something bad once in a while
You shouldn't destroy other people's property. When the person finds out their tire is deflated they will be upset and cannot drive.
It's just going to one day, I don't think they will find out. Besides they probably won't notice.
They definitely would notice their tire being deflated. You should just leave their car alone or you're going to get in trouble.