When you put your penis and testicles in your significant others anus.

Female Masturbation
See Stuffing The Chicken

When you rapidly finger your girls pussy

Trying to have sex with a limp penis and attempting to cram the phallus into a vagina, usually while intoxicated.

When all three of a girl's primary orifices are filled with the genitalia of three other men and/or animals. This is most commonly found when a female is having a foursome with three other individuals (male) with questionable sexuality.

v. Stuffing the Turkey is a gang-bang involving at least four men. It also involves a 20 lb. Butterball turkey. The men take turns humping the living hell out of the turkey, and when all men present have "finished", the turkey is oven roasted in the usual fashion and served on Thanksgiving. Preferably to relatives that you are not fond of.
Although this originated in Eastern Russia, it is often contributed to Norway.

Stuffing the Turkey is an act in which someone scoops mashed potatoes in their hand and inserts the hand in a vagina. It could also be inserted into anus and thats stuffing the Turkey with Gravy.