While the bar patron savoured a double martini, an attractive women sat down next to him. The bartender served her a glass of orange juice, and the man turned to her and said, "This is a special day. I'm celebrating."
"I'm celebrating, too," she replied, clinking glasses with him.
"What are you celebrating?" he asked.
"For years I've been trying to have a child," she answered, "Today my gynaecologist told me I'm pregnant!"
"Congratulations," the man said, lifting his glass.
"As it happens, I'm a chicken farmer, and for years all my hens were infertile. But today they're finally fertile."
"How did it happen?"
"I switched cocks."
"What a coincidence," she said, smiling.