Bum fire

Similar to its bon fire counterpart, a bum fire involves a pollutant-ridden fire cast in an open steel barrel trash can (make up of trash container is flexible), that a multitude of of skeezy homeless personnel can find warmth, scavenging light, or a cooking surface to decoct the day's loot over. Also known as a hobo heater

The flame cum fire bum is when you drizzle gasoline in and around the anus of your partner and then light a match and put it into your urethra and proceed to butt fuck your partner.