1) When having sex with a girl doggy style, the man lights a cigarette and puts it out on her back so it leaves a burn. Then right as he's about to cum, he'll jizz on the burn spot to cool down the burn.
2) When having sex missionary style the man lights a cigarette and sets her bush on fire with the cigarette, and then puts out the fire with his jizz.
In both cases after the burn/fire is put out you must say " Only You Can Prevent Forest Fires"
"Man I caught her bush on fire, and totally went Smokey The Bear on her Ass"