After having 69 with his lass Gary remembered that he had a Dentist appointment.
Afraid they would smell fanny on his breath, he brushed his teeth,used dental floss, a bottle of listerine and ate a packet of strong mints.
Feeling confident in the Dentist chair, he opened his mouth.
The Dentist got close and said "Did you have a 69 before you got here?"
"How did you know?" Gary said. "Does my breath smell of fanny?"
"No" the Dentist replied, you have a skidmark on your forehead