True Story:

I lady had a cat.  It was an indoor female cat that had never gone out of the house.  One day the lady notices that the cat was getting rather big around the belly, so much that it seemed it was pregnant.  To be sure she called a vet who came to examine the cat and he confirmed that it was in fact  pregnant.    "But that can't be" the lady said, "he's never gone out and he's never had company".   "Are you absolutely sure?" the vet replied, "Maybe he sneaked out when you weren't looking."   But the lady was quite sure that her cat had not had any relations with other cats.   While the vet rubbed his chin in amazement another cat strolled by him.  "Wait a minute!" the vet yelled, "Who's that?!"   "Who that?," the lady said calmly, "That's just her brother".  :)

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