After being killed in a first-person shooter video game, such as Halo or Call of Duty, when your (female) opponent squats repeatedly on you, imitating the act of dipping her vagina on any or all of your body.
Rather humiliating, especially when there's more than one of them doing it. Because, come on, you just got pwned by a girl. Even though there are no girls on the internet.
Other popular pseudonyms for this particular phenomenon include: clambag, taco bar, fish smear, etc.
Buhbuhbam13: That's not teabagging idiot, that's what is called a "beaver scrape." She probably digs you man! ;)
FunkmasterFritz: Whatever the fuck. I don't care. I'm gonna assassinate that bitch when I spawn.
Stefunny85 (girl): *rolls eyes*