When a man is sufficiently obese that his penis can be engulfed in body fat, allowing him to stimulate himself by simple, repeated shifting of body position. This auto-erotic action is fatsturbating.
When a young man takes a break from jerking off. Fasting like a jewish person during Yom Kippur, a fasturbation may take a few days a week or to a more experienced fasturbator up to a month.
Guy 1: dude im sorry ive been so short tempered lately, i've just been in a fasturbation contest with my dad.