Younger Brother Fat Syndrome. This syndrome affects younger brothers, especially youngest brothers in a family with all boy siblings, that are significantly heavier than their older brothers.
Did you see Johnny's younger brother waddling out of McDonald's? He's Twice the size of Johnny! What a case of Y.B.F.S.
Did you see Andrew's brother with YBFS fall down? He's so heavy he couldn't even get back up! He just rolled on his back like a turtle until some fire fighters came and helped to lift him back up!
Did you see Andrew's brother with YBFS fall down? He's so heavy he couldn't even get back up! He just rolled on his back like a turtle until some fire fighters came and helped to lift him back up!
by Dr. STOP YBFS March 5, 2011
Get the Y.B.F.S.mug.