Jill tests her sister's desire to be a slut through more .

Fifteen minutes later, Jill, Annie and Arthur laid out on the bed, three sweaty nude bodies, post-coitus. Annie laid in the middle, and her hands reached down and fiddled with her husband's limp, exhausted cock. Behind her, Jill reached down and fingered her ass gently, milking a bit of cum from it, then bringing her finger up to her mouth and slicking it off.

"That was the most amazing sexual experience of my life." Annie said.

Jill smiled. "It's nothing compared to what lies ahead if you're going to be the biggest slut on the planet."

Annie greeted that idea with a big smile, and then immediately seemed embarrassed but proud. She looked her husband deep in the eyes. "Am I allowed to Daddy? Am I allowed to be the biggest slut in the world."

Arthur nodded.

"You don't mind that it means I have to fuck lots of other men?" Annie said timidly.

"I don't mind" Arthur answered. "As long as I'm always allowed to watch."

And Annie shuffled in bed, turning toward her sister. "How many?"

"More than you could imagine." Jill answered. The though of her good older sister getting into unending kinds of sexual pleasure made her wet again.

"How many have you fucked?" Annie asked, as she gently rubbed Jill's nipples. Jill wondered if it seemed odd for Annie, almost as if she were rubbing her own. Their breasts were very similar.

"Hundreds." Jill answered. And Annie met her answer with a nervous gulp. Jill brushed a strand of curly black hair from her sister's face. "Sometimes being a slut isn't about quantity. Sometimes it's about what you're willing to do." And Annie nodded. "Tell me how you started playing daddy and daughter?" Jill asked.

"We always had" Annie answered. "Ever since we started dating. Arthur liked to be called 'daddy' and he was really good in bed so I humored him. Then slowly I really started to like it too."

"How did the kids enter into it?" This was something Jill was dying to know.

Annie shuffled shyly. Despite some naughty inclinations Jill was still going to have to work on her a bit if she was going to become a giant slut. "One day... really not too long ago, Ruthie was going out on a date and she was wearing this dress that just really showed her off. I don't think Art or I had really noticed until that point what a well built woman she'd developed into. And as she was leaving the house with her boyfriend I noticed Art taking kind of a long look at his daughter." Now it was Arthur's turn to shuffle uncomfortably. Annie went on. "That night, we were making love and I was calling him Daddy and in a moment of joy I told him to call me Ruthie. He was shocked at first, but I knew he wanted to do it and I knew I couldn't take it back. It wasn't long after that that I started calling him Jake sometimes too. And then it just became part of our sex life."

Annie explained it in such a matter of fact way, as if there were nothing crazy or kinky about it at all. But Jill knew that a mind that could accept doing that, could accept anything. It was time to push a little. "Every consider making it a reality?" Jill asked.

Annie looked confused at first, then understood the question, "No! Never! I mean... never! It's one thing to do something between just us, but with the kids? Never!"

Jill had expected resistance. It's okay, she thought, Annie changed her tune before when Jill had started ordering her around. She'd do it again. She was a classic submissive. "Why not?" Jill asked. "They're both of age. You're both attractive parents. Maybe they'd like to."

Arthur stayed silent. Annie shook her head. "I just... I couldn't. I'll become a slut. I want to. I want to do crazy adventurous things. It's true. But I can't allow it to involve my kids... ever."

Jill smiled. "So you're saying you'll do lots of things, but that's something you'll never do."

Annie nodded. "I'm saying never."

The next day, Jill stood in Annie and Arthur's living room, dressed in only a bra and a smile and gave the order, "Now slide off your mother's panties and take a look at her amazing pussy."

And a pair of trembling 18-year-old hands reach over to Annie's hips and slowly slid down her underwear.