A girl was a prostitute, but she didn't want her grandma to know.
One day, the police raided a whole group of prostitutes and the girl was among them.
The police had all the prostitutes lined up when the girl's grandma came by and saw her granddaughter.
Grandma asked, "What are you lining up for?"
Not willing to let her know the truth, the girl told her grandmother that some people were passing out free oranges and she was lining up for some.
Grandma wanted oranges too, so she went to the back of the line.
A policeman was going down the line asking for information from the prostitutes.
When he got to grandma, he was bewildered and asked, "You are so old, how do you do it?"
Grandma replied, "Oh, it's easy. I just take my dentures out and suck them dry."