1
When two people go at it with their butts, using a smelly mouth or a stinky vag, but mostly a butt that's either clean or messy, and the guy stuffs his sperm into the other's butt like it's a piggy bank.
My cousin packed pennies and then cried for 10 minutes because he felt like a failure.
She said she packed pennies in the back of the bus and got caught by the teacher.
He packed pennies with his sister and got grounded for a week.