Q: What do you call cheese that isn’t yours?
A: Nacho cheese!

Explanation:  Nacho cheese is a form of processed cheese sauce mixed with peppers and other spices.  It is used to make Nachos, a snack made with tortilla chips and there are many ways to make them.  When you say “Nacho” it sounds like “not your.”  So, if it’s “Nacho cheese,” that sounds like “not your cheese;” cheese which isn’t yours!  Try some nachos; they’re great!