When you're asshole is like Mount St. Helens and is ready to explode like a volcano.

When a partner inserts rubbing alcohol into a stretched asshole and lights it on fire then the partner farts out the alcohol making a fiery explosion. Ass volcanos are known to cause permanent damage to the asshole.

The move used by all the rap video dancers. Done by standing in place and shaking your ass rapidly.

when a girl shoots cum out of her asshole like a volcano the cum is always steaming hot

An ass volcano is the act of inserting baking powder, vinegar and red food coloring to a gaping asshole (normal it has been stretched out from a vigorous session of anal sex). Once the ingredients have been inserted you will have a grade 7 caliber explosion that even an all taco bell diet can not top.