After having a 69 with his lass, Bob remembered he had a dentist appointment.
Afraid the dentist would smell fanny on his breath, he brushed his teeth, used dental floss, a bottle of Listerine and ate a packet of extra strong mints.
Feeling confident he sat in the dentists chair and opened his mouth.
The dentist got close and asked "Did you have a 69 before you got here?"
"How can you tell?" asked Bob "Does my breath still smell of fanny?"
"No" replied the dentist "You have a skid mark on your forehead"