A woman promises to teach her boyfriend what 69ing is.
He lies on the floor and she squats down over his face to assume the position and farts. Embarrassed she stands up and apologises. She squats down for another go but farts again, she gets up and apologises again.
Before she can have a third go, her boyfriend gets up and goes to walk out saying “yeah this isn’t really for me, I’m not having 67 more of those in my face”