[interesting]

Sarah was on her back, her buttocks raised up by the pillows, while Mary was getting ready to use the strap-on on Sarah's ass. It was lubed up, ready to do its deed. We were all around, waiting to see what would happen, how it would feel for Sarah. Tom was still tied up to the chair, still hard after Sarah had let him go, looking on, curious. The rest of us were silent as well.

Mary settled the tip of the dildo against Sarah's rectum.

"Relax into it," Mary said.
"I'll try."
"Do you trust me, Sarah?"
"I do. I don't know what's gotten into us lately..."

There were no more words spoken between the two. Mary got to what she intended, and Sarah squirmed under the stress of something trying to enter her backdoor; Mary teased Sarah's clitoris with her fingers to make Sarah more receptive, and it worked a bit. The pressure from Mary's weight made the tip slightly disappear. Sarah groaned, and it was unclear if she was enjoying it. But it was now a done deal, as Mary grapped Sarah's waist with two hands and started slowly pulling her onto the shaft.

"oh f..."

Sarah was unable to voice more words, as her face contorted with a strange expression which we had never seen there.

"Too much?" asked Mary, sounding concerned.
"No... it's just... it's bigger than a marker..."

Mary resumed her operation, as gentle as before, and Sarah's face slowly shifted from pain and confusion to acceptance. She bit her lower lip, keeping her eyes closed. It took a few more moments for Mary to stop, with only half the strap-on inside.

"How does it feel?" asked Mary.
"Okay... bigger than it is, actually..."
"You still good?"
"Yeah... you enjoy this?"
"I do... I hope you will too."
"Ok... I'm ready."

And the next movement was in, as Mary started to sway back and forth, the dildo sliding in and out, starting to have the desired effect on Sarah. She moaned slightly, breathing heavily in-between strokes.

"I so want to try that!" Jennifer said to me.

I stayed quiet, watching, wondering what kind of pleasure one could derive from it. Sarah didn't seem to enjoy it too much, but her face no longer lingered in pain. Mary was building up steam, driving it increasingly faster in and out of Sarah.

"How is that?"
"I can... handle it, I guess... women like this?" Sarah was able to reply.
"Some do... Hang on."

With one hand, Mary started playing with Sarah's clitoris, and this time, there was a very obvious reaction.

"Oh my....!"
"A-ha! Now you get it..."

Mary was doing it, and Sarah was appreciating the actions taken upon her. We saw her eyes rolling back as her body arched and swayed under Mary's impulse. After several seconds of this anal penetration and clitoral stimulation, Sarah was on the brink of orgasm; Mary stopped abruptly, and Sarah got angry.

"Ah! Fuck... why'd you stop?"
"You're my slave, Sarah... I decide when you get to come..."
"Fuck... fine..."

Sarah took a moment to regain her composure.

"What now, mistress?"
"Now that you're good for the idea, we're going to step it up a notch."

Mary turned to me.

"Untie Tom."

As I proceeded to do so, she turned to her brother.

"Okay, bro... you want to make your point, so I'll ask one more thing from you."
"Ok."
"We've done a lot together, we've always been really close... up until recently."
"Yeah, so..."
"So, we're going to be doing something on Sarah - together."
"Like we did with Claire at your birthday a few years ago."
"Yes, but not quite the same..."

Sarah seemed as puzzled as we were. Mary lay down on her back, motioning to Sarah to come over.

"I want you to impale your pussy on my strap-on, Sarah."
"Could you clean it up first? It was in my ass..."
"Sure."

Mary complied, wiping it off with a wet washcloth. Sarah moved into position, crouching down on Mary, who spread her legs to her sides as far as they could go; they were actually bent in front of Sarah. It was an intruiging sexual position. Sarah lowered herself onto the artificial shaft, holding her weight so she would not crush Mary. We saw Sarah's pleasure rise as the dildo disappear inside her.

"Good," Mary replied. "Tom, you have perfect access to her ass now..."
"What?" Sarah asked.
"Tom's going to fuck you in the ass..."
"But he's too big..."
"No he isn't. I got you ready for him."

It was time I intervened.

"Hang on, Mary! You want Tom to fuck Sarah in the ass while you..."
"While I fuck her pussy, yeah..."
"Sarah?" I inquired.
"I'm okay. I'm kinda curious. Tom?"

The main man was silent for a while, but he shrugged it off and moved behind Sarah.

"You're okay with this, right?" he asked.
"Yeah... have you ever done this before?" Sarah inquired.
"um... yeah."

We were all stunned by the answer.

"I mean, not the double-team thing, that's new like this," he precised, "but anal yeah..."
"Ok... Be gentle."
"I will."

Sarah was eager for Mary to start using her, but Mary was waiting for Tom to be in position. He knelt behind her, his cock still hard, steadying himself. As he was lining up, Mary called out to him.

"Tom, no holding back."

He nodded. At first, it seemed like his manhood would not fit, would not enter. Tom went at it, slowly, wiggling the tip until something finally happened; it gently slid in, making Tom and Sarah moan at the same time. It took him moment after that to slide half of his dick inside Sarah's ass, while the strap-on occupied the whole of Sarah's pussy.

"oh my God!" Sarah squealed.
"Does it hurt?" Mary asked.
"Yes... no... I don't know... oh..."

I was shocked and extremely excited. My friend Sarah was being double-teamed by the twins Mary and Tom; I witnessed with trepidation as they started pumping inside her, alternating. Sarah was torn between pain and bliss, but pleasure was winning out. I cast a quick look around the room; Jennifer was busy masturbating to the sight; Claire and Cassie were looking on, unsure if they were enjoying the scene or not. Tom and Mary, however, were lost to the moment, as was Sarah, heaving and panting as she was taken by her two partners. Even Mary seemed to derive some form of pleasure from it.

It took a moment, but Sarah finally achieved the pinnacle of pleasure, repeated moans giving it away. Tom, now completely lost to the moment, only lasted a few seconds after that, spending himself fully inside Sarah's ass. Seeing him orgasm reminded me how incredible it had been when my previous partners, their dicks between my cleavage, came hard and shot their loads across my chin. And even though Tom was done, he kept at it for a long moment afterwards, sustained by the energy of the double motion with his sister inside Sarah.

Sarah bent down, kissing Mary as more pleasure was given her. Finally, the trio stopped; as Tom pulled away, we were treated to the disgusting sight of his white cum dripping from Sarah's ass; I looked away, focusing on Sarah and Mary, still kissing. As they pulled away from each other, I could sense the electricity between them, still very much alive.

"That way," Mary whispered, though we all heard, "you'll never forget me."
"I'd never forget you even without this, Mary..."

I had guessed right. Sarah was in love with Mary, or at least in lust of some kind. I turned to Tom. He seemed completely out of it, retreating to his chair, satisfied but confused. I moved towards him.

"Are you okay, Tom?"
"Yeah... sure..."
"You don't look okay."
"It's just..."

He paused, looking at me, almost judging me. He shrugged his shoulders for a moment.

"I'm not... much... into..."
"Yes?..."
"uh... girls."
"Oh!"

It took me another moment to process his comment, and then everything I had observed since his arrival fell into place.

"But did you enjoy it?"
"I guess... I came. I can have sex with girls if I want to... I just... don't really want to."
"Ok. Wow. I didn't know."
"What about you? Do you prefer boys or girls?" he asked me.

I couldn't answer.

"I don't know... I like both but..."

I looked down at his limp dick and smiled.

"I guess I like cocks... A lot."
"That's cool," he said.

By now, Sarah had pulled herself off of Mary and was resting on her basement couch. Mary was removing the strap-on, flushed from her exercise. Cassie immediately stole the tool from her.

"Mine... you're done with your slave, Mary, so you're mine now..."

Mary turned to face the red-head, who was putting the strap-on belt around her waist.

"You waste no time!" Jennifer said.
"I know what I want, and I want it now. Mary, on all fours, now!"

Mary complied, and Cassie moved behind her. She seemed to on fire, moved by a never before seen energy driving her words and actions.

"I'm going to take you and fuck you, now... first in your pussy... then your ass... and while I'm doing that, you're gonna eat someone out!"

She looked at Claire.

"You, Claire... she's gonna eat you."

Claire hesitated but moved towards them, placing herself on her back to give access to her pussy. Cassie was all about control now, and Mary was now going to pay the same way she had made Sarah pay. And once more, I couldn't tear myself away!