Little Bobby walked into his parents' bedroom while they were making love.
"What're you doing?" asked the child.
"Why, 'er, we're playing poker, son," replied his father.
"What's mama doing?"
"She's my partner."
Bobby ambled out of the bedroom, and as he walked down the hall, he heard noises in his sister's bedroom. He stopped, opened the door and discovered the girl having intercourse with her boyfriend.
"What're you doing?" asked Bobby.
"We're playing poker," replied his sister.
"And what about him?" asked the child, pointing to her sister's pal.
"He's my partner."
The youngster left the room and went down the hall to the room of Roger, his teenage brother, who was masturbating furiously.
"What are you doing?" asked the child.
"I'm playing poker," replied Roger.
"Where's your partner?"
"Listen," said the older brother, "when you've got a good hand, you don't need a partner!"