Jimmy: I was eating your mom!
Bob: Well I was eating your mom’s mom!
Jimmy: Well I ate your mom, your mom’s mom, and your mom’s mom’s mom!
Bob: Your mom’s mom’s mom’s mom.
Jimmy: *freaking disintegrates*
By Dorthy
Your Mom's Mom's Mom
The insult used after "Your mom" and "You mom's mom" have already been exhausted. It is often used by small children that do not grasp the full scope of comebacks.