You call on a friend that is not liked by your circle of friends, but is always around anyway. Get them really drunk. Find a dead girl (don't try at home) and place her freshly (1 to 2 days old is the best) dead body in a different room on a bed. Have several friends hide in the closet of said room. Tell your friend (victom) that there is a really drunk girl in the other room sleeping and if he orally pleasures her he is guarenteed a bit of "the ol' in and out." Now when you friend starts to get busy on her south bound action all you friends come running out the closet and jump on her stomach. This makes all her internal organs (or mong as it's called after death) come out her box and into his mouth! Hence, the Mongolian Buffet.
never heard of anyone doing the Mongolian Buffet, but my ears are open