Haha, I'll never forget when I got my poor cousin in trouble. We used to flip each other off all the time as a joke. His mother is like 5'3 and tiinnnyyy. She saw him flip me off (I had done it first) and FLIPPED out on him. Meanwhile, he's taller than she is and he's literally crapping his pants. I'm trying to tell her I started and she said he's supposed to know better, blah blah blah. Like she wouldn't accept that I did it first.
I apologized to him later that I got him in trouble. We flipped each other off and laughed about it.