The soft squeal the girl made came to Lisa and Johnny as she pulled her mouth upward. She held the very tip of her father's cock between her lips, pumping fast and hard on the shaft. The man grunted, and the girl squealed again.
Lisa and Johnny saw the man's come juice dribbling from the girl's sucking mouth, smearing over her jacking fist.
Johnny muffled grunt as his cock spurted into his mother's cunt.
Lisa rammed her knuckles into her mouth as she came, her pussy squeezing at her son's rapidly spurting cock, her orgasm very strong.
They did not stay to watch any longer.
On the sidewalk, hurrying home, Lisa said, "Johnny, I think I've just found a little sister for you."
"You mean that girl back there, Mom?"
"Yes. You and I are going to become very friendly with them. I don't mean to marry the man. Although that could happen. But in the meantime, you can pretend you have her as a sister."
"But, Mom, that would mean you'll fuck her father, too."
"Isn't that okay?"
"Yeah!" Johnny said, grabbing his mother's ass. "That would be great."
"Tomorrow, we'll try and meet them."