four flat tires 

For pizza delivery drivers - when invited into a house for recreational activities, this is the code used to let their manager know they won't be back as soon as expected.

Hey boss, I'm gonna be late for the next run. I've got four flat tires.

Alright - just make sure you use protection.

four flat tires by newsedition November 14, 2013

four flat tires 

To be close friends with another.

James and I are down like four flat tires.

four flat tires by hogan468 June 9, 2006

down like four flat tires on a dump truck 

Means that you are cool about doing something.

Mike says: Hey are you down to go to the movie tonight.

Rashad says: I'm down like four flat tires on a dump truck.

down like four flat tires on a dump truck by Larry Scott January 3, 2008