When a women shuves a buttery dildo into her anus, she contracts her but muscles so the the butter oozes out. This is tipicly stereotyped to fat or obese women. An extention of this is when the used butter is used on toast
Jenny was a fat bitch who liked to give herself anal combustion
by Imakeupstuff August 06, 2012
Any form of explosion just inside the anus. Could be the result of inserting and igniting gasoline or gunpowder, attempting to light a fart, or that Mexican food from yesterday. Depending on the strength of the sphincter, severe anal combustion may result in blowing out the anal socket or rupturing of the rectum.
I had pretty bad anal combustion after that spicy 15 bean soup--it almost blew out my sphincter!
by b007y514y3r March 11, 2016