your mom is a joke format that people use to make the other have to come up with a comeback
your mom is so fat she made the earth go out of orbit
The most common comeback ever in history.
Person 1 : What is your favorite color?
Person 2 : Your mom is my favorite color. ;)
The only come-back you'll ever need
Bully:your gay
You:no your mom
Bully:"dies"
Your mom is fit I have sex with her every day
I AM YOUR FATHER