He's 87 and she's 86 years old. They just got married and are on their honeymoon.
In the Hotel room, she slips into something sexy, and crawls into bed, and waits for her new groom.
He's in he bathroom sprucing himself up.
She waits, and waits 'til she can't wait any longer. She gets up and goes to the bathroom and opens the door.
Peering in she sees him bent over on the toilet trying to put on a condom. She asks "Honey, what are you doing?" and giggles. "I'm 86 years old and can't get pregnant anymore."
He looks up at her and says, "I know, but honey, you know how the dampness effects my arthritis."