What's your inside joke?

Explain it or not, your choice.

There’s that one phrase you can say to someone, and you’ll both explode into fits of childish giggles. What is it?

“You struck me!” – A play fight gone physical.

“Grandpa, you’re an asshole!” – from a 3 year old to his almost 7 foot tall, war hero grandfather.

“Flush flush!!” – Best friend got caught at his high school girlfriend’s house – because the condom backed up the toilet! Ah, teenagers.