Atosa also Atusa is a Persianfemale name commonly found in Iran and in Afghan speakers of Farsi/Parsi, meaning beautiful body. Alternative spellings are: Atoosa, Atousa, or Atossa.
Atosa was the daughter of Cyrus the Great and a half-sister of Cambyses II. She later married Darius the Great and gave birth to Xerxes the Great.
When one takes his penis from one girl's ass and inserts it into her sister's mouth. Or his sister's mouth. As long as the other sister is a relative of one of the participants, it is officially ATOSM.
What happens after you look up some form of disgusting porn with your friends: Your computer is plauged with millions of viruses so that it won't work correctly anymore...
This is useally the effect from watching to much scat porn with friends just to see if you can make yourself throw up. Also apples to other videos like pain olympics and such.
Some awesome kid: OMGZZZZ my computer won't work. Mom, get in here, something is wrong with the computer!!!
MOM: Looks like your computer has come down with a bad case of Scat-porn-atosis, Jimmy.
Jimmy: Damn, and here i thought i could easily feed my poo fetish via t3h internet...