"So that's how you got the idea for this," he said after she had finished.
"No, silly," she giggled. "I didn't even know you were in town, remember?"
At first David was surprised that his cock had stayed so hard. But he wasn't surprised now. The details that Marsha told him about fucking with Kirstie, with Rick, and with both of them together aroused him fiercely.
He scooped up her incredibly firm breasts again and began sucking and tonguing her soft nipples while she talked. In only a few seconds she was panting again. She swirled her wet pussy around on his prick.
"God, you're still so hard!" she said. "Let's go in on the bed. I really want you to ram it in to me this time."
They got up off the sofa. David followed Marsha into her bedroom. She shut the door behind them.
"Why did you do that?" he asked her quizzically.
She came into his outstretched arms and pressed the full length of her naked body against his. They gave each other a long smoldering kiss. David's hands dug into her round smooth ass. She massaged his balls and squeezed the pulsing shaft of his cock.
"I want to trap you in here," she giggled. "And never let you go. I want to pretend that you're going to fuck me forever, and never fuck anybody else."
"But what about my wife?" he grinned, bringing one hand around between her thighs and hand-fucking her slowly. "What about Debby?"
"She doesn't have to know anything about it," Marsha pouted playfully. "I suppose you'll have to fuck her once in a while. She'll expect it." She undulated her phenomenal body, rubbing her naked breasts against his bare chest. "But you can think of me. You can pretend it's me."
"I don't think I'll be able to help it," David said, sinking his teeth into the smooth strip of muscle along her shoulder.
"Ouch!" she squealed happily.
She inserted his stiff cock into her runny slit and they began fucking slowly, still standing next to the bed.
"And maybe I can come down and visit you on vacations," Marsha panted. "And you can send her out for groceries or something, and we can fuck like crazy before she gets back. Uh! Oh, that feels goad!"
But David still couldn't get out of his mind the erotic possibilities she had described when talking about herself and Kirstie and Rick. After all, his wife Debby as a beautiful woman herself. Just think of being in bed with the two of them at the same time, his wife and his sister! The very thought of it made his already stiff prick swell and hammer violently.
"Or maybe we could persuade her to do it with us," he suggested, breathing in Marsha's ear and frenching it at the same time.
"Oh!" Marsha gasped. "Oh God, wouldn't that be beautiful?"
She began writhing more heatedly against him, jamming her soupy cunt down on his up thrusting meat.
"Oh baby, baby!" she moaned. "But right now just fuck me. Hold me tight and fuck my cunt hard, hard!"
She drew him down onto her bed. Her golden thighs yawned open to receive him. She lifted her legs and locked them around his neck, wanting to feel the fullest penetration possible. Her body melted with love for her brother, and when he slid his long cock into her she began to boil over immediately with skimming spasms of coming.
"Oh yes, oh yes!" she whimpered into his ear as they began a slow simmering fuck that soon became a holocaust of surging, rupturing orgasms.