A dentist noticed that his next patient,  a little old lady,

was nervous, so he decided to tell her a little joke

as he put on his gloves.  

'Do you know  how they make these gloves?' he asked.  

'No, I don't,'  she replied.  

'Well,' he spoofed, 'there's a building in  Canada with a big tank of latex, and workers of all hand  sizes walk up to the tank, dip in their hands, let them  dry,  then peel off the gloves and throw them into boxes of the right size.'  

She didn't crack a  smile.  

'Oh, well. I tried,' he thought.  

But five minutes later, during a delicate portion

of the procedure, she burst out laughing.  

'What's so funny?' he asked.   

'I was just envisioning how condoms are made!'   

(Gotta watch those little old ladies!

Their minds are always working!)