When you have a shitty fapping session.

It's the 2nd pie in the famous two for $1 deal at Mickey D's. After you've finished your entree and your 1st pie for dessert, open the box of the remaining pie and insert your penis. While securing the closed end of the pie box with your index and middle fingers, fuck the pie.

When a male ejaculates into an apple pie before it's baked.

Fapple refers to using an apple (either the fruit or companies products) to assist in masterbation.

Apple is the action of fapping into a Snapple. A Snapple of any flavor.

When you masturbate into a snapple (got the idea from Philip DeFranco)

When you masturbate into a Snapple.