The 12 Days of (Xmas) Cumming!
On the 9th day of cumming...enjoy the Dickens out of an erotic holiday story!
Go to an erotic story archive (such as nifty.org or asstr.org)! Find some erotic holiday stories using search terms such as "Xmas" or "Christmas", and pick one that has a title which appeals to you. Don't look at the length until you begin reading. You may switch to a different story if you don't like the content/writing, but you can't switch based on length.
If you have a masturbation sleeve such as a Fleshlight or Tenga, use it while reading your story. If you don't have one, don't worry - you can use your non-dominant hand (the one you don't usually stroke with) to fap! You must be stroking, even if slowly, the entire time you're reading!
Depending on the length of your story, it may be difficult not to cum! You MAY cum early if you need to, but you must take a 15 minute break (or more if necessary) and then resume the story. Even if you came earlier (even multiple times), you must cum again as soon as you finish the story.