When you stick one or many fingers into your own anus and take the fecal matter from your rectum. With your finger covered in poop, you stick it/them in her vagina while simultaneously fingering her. Repeat the process until her vagina is either full or until she has climaxed.
i stuck my own finger in my ass, now im gonna take my poopfinger and shove it in her pussy. thats called giving a stuffed shell.