anus on fire!
During the course of pleasurable anal activities, the impact is so great which causes a heat rash around the outer and inner regions of the anus. It causes the hair that grows around and sometimes inside the anus to burn away. In the worst case the flames go all the way inside the anus and it turns black.
Ho lad, slow down or else it causes an 'anus on fire!'
Anus Fire
When playing call of duty and in final stand a person shoots and it looks as if flames are projecting from the anus
dude look at that anus fire!