What is Slow Down Tubby, You're Not On The Moon Yet?
1.
A prase used when an over-weight person is consuming a large ammount of food, because On the moon, we would weigh much less than we do here on earth.
Tommy,a rather over-weight child, is stuffing his face with pie. His Older brother remarks, "Slow down tubby, you're not on the moon yet."
See