When you get your male partner's penis erect, so that it becomes parallel to the floor. Then you put a line of cocaine on top of the penis from the tip down to the shaft, and you begin to snort the line from start to finish. Hence the Columbian drag race.
"Hey, we don't need any mirrors, we could just do a Columbian drag race off our cocks!"
"Im very hard right now, I think I have enough to let you do a Columbian drag race off me"
"Yo, we're going to have a group orgy
, you can come too, we'll have a couple drinks and then maybe we can do a few Columbian drag races off each other"