An inside joke (or an in-joke) is a joke whose humor is only funny for the people involved.
If you experience an inside joke as an outsider, it's more confusing than it is funny.
However, surprisingly enough, when an inside joke is explained to you, it can actually be really funny.
Most likely, you share at least a couple of inside jokes with your own family.
Is there an event, word, or situation that would be unfunny to anyone else outside your family?
That's an inside joke! Tell us about it in the comments below.
Your family story could be included in a post!