BB Tattoo
 

A woman is frustrated with her love life because her husband has a massive crush on Brigitte Bardot. To win back his attentions, she goes to a tattooist to have the letters 'BB' tattooed on her boobs.
The tattooist warns her that age and gravity would probably make this unattractive later in life, and suggests the tattoo on her butt instead. She agrees, and bends over to receive a 'B' on each buttock.
When her husband gets home from work that night, she greets him by turning around, bending over, and lifting her dress to expose the artwork.
"What do you think?" the wife says.
"Uh, who the hell is Bob?" the husband replies.

and why is his name on your ass?