pack sand up my ass
When you tell a bunch of fake stories and your ass is so full of lies it's like a beach party in there.
I said I was rich. I had a lunch from the cafeteria. I packed sand up my ass.
He said he was a superhero. He tripped over a sock. He packed sand up my ass.
She said she was a rockstar. She played a kazoo. She packed sand up my ass.