What does Bexar County Backfire mean?

Bexar County Backfire meaning in Urban Dictionary

The expelling of gasoline from a person rectum after said rectum has-been filled with air from their particular lovers lungs. Often performed while tossing salad. Found by Sam Mangum circa 1997 in Universal City, Tx. Known for not a wonderful experience. Also called a Bexar County Backblast or B.C.B.