look up any word, like blumpkin:
 
1.
the act of having 3 or more people cumming inside your butthole
then pouring it into a cup
and drinking it
damn
we just burst into that bitches ass and put her over a cup and make her drink the shit
she said it was a good anal milkshake
by prestige skillz ryder August 27, 2009
 
2.
Watery and often violent diarrhea. The sound of excreting said milkshakes in public restrooms can often be mistaken by other patrons as that of someone vigourously mixing actual milkshakes (Unless it is accompanied by screams or loud groans of agony).
I'm sorry, we're out of milk, but, if you like, I could make you an anal milkshake.
by Kool-Moe-Dee January 19, 2011