Tex, it's probably from when you accidentally bit the inside of your cheek while you were stuffing your face with pie. Clearly what you need is a little "hair of the dog"--bite that bad boy again, and suck out all that pus. Spray in a little whipped cream straight from the can to mask any flavor issue you might have.
Be sure to poke and prod around with your tongue afterward, and feel free to squeeze the sore between your teeth to milk out every last drop of pus.
Oh, and don't forget to describe in excruciating detail just how the mixture of pus and whipped cream felt, smelled, and tasted.
