Amber may have thought she was able to handle it, but she vastly underestimated a futanari's stamina. It didn't help that her new pussy fit Maddy's cock like a glove and caused her to experience far greater pleasure than her origional, smaller one. They just finished their third round when Amber finally runs out of energy and needs a short break. Maddy understands, knowing full well that her limits far supersede those if a normal human. So she gets up and heads to the bathroom while Amber lays exhausted on the bed, recuperating her strength to continue on after their break.
The moment Maddy closes the bathroom door, she finally breaks character and can't stop herself from smiling happily. She finally found someone who not only does she fit inside of, but who actually seems to be enjoying it as much as she is. Her previous partners have always talked a big game, at least until she entered them. Then they always would tough it out for the first round, but then bail immediately afterwards due to their vast underestimation about how truely huge her cock really is.
One comment that one of her one night stands said to her, which she still often laughs at, is that "it felt like I was fucking a cock shaped wine bottle." Well at least size wise, she wasn't exactly wrong. Maddy knows that cock is about that size in diameter.
Maddy finished emptying her bladder and went to wash up when she noticed a phone sitting on the counter. She picks it up and it instantly opens, as Amber never set a lock on it. All that was displayed was a single sentance:
"Amber is at her limits, but doesn't want to disappoint Maddy and quit on her early."
"The fuck?" Maddy was instantly curious as to how this phone knew such things. She tapped the screen and a keyboard popped up allowing her to edit the text. "Well, Amber did say she just needed a short break, so she should not be at her limits. Let me fix this BS sentence." She changed it to read:
"Amber is no where even close to her limits, and cannot disappoint Maddy, nor quit on her early."
"There, that's better." But then before she set down the phone, a new sentance generated:
"Amber is fisting her pussy in desperation as she waits for Maddy to return and fuck her some more."
"Woah, that's quite a sentance." Out of curiosity, Maddy peaked out through the crack in the door and sure enough, Amber was seriously going to town on her pussy with her entire fist popping in and out of her gaping wet hole. "Huh?" Maddy was a bit surprized. Amber specifically had requested to not be fisted earlier. So why is she doing it now?" Maddy closed the door again and corrected the sentance:
"Amber is sitting like a good bitch as she obediently waits for Maddy to return and fuck her some more."
Satisfied, Maddy set down the phone and left the bathroom. She took 2 steps before she stopped completely in her tracks as she saw Amber sitting down on the floor, like a dog, with the collar on, leash in her mouth, and the tail plug they were using earlier already shoved back inside her ass.
"Hey, weren't you just fisting yourself just a moment ago?" Asks Maddy in disbelief. Amber cocks her head to the side and looks at Maddy as if she said something crazy. "No, I have been waiting right here this whole time, like you said to. I am a good bitch, and just followed you instructions."
"What instructions?"
"You told me to Sit and Stay while you went to the bathroom" explained Amber innocently. Then she thought of something. "Hey, you didn't happen to see my phone in there, did you? I think I may have left it in there on the counter."
Maddy goes back and gets the phone and hands it to Amber. "Thanks. You didn't open it, did you?"
"Kinda, sorry."
Amber looked up at Maddy with a worried expression on her face. "You did? Did you do anything?"
"There was a few weird sentences about you, so I just corrected them is all. But that's all I did, promise."
"Shit. Do you remember what you did at least? It is pretty important."
"Yeah, why?" Maddy now was curious as to why those nonsensical sentences were so importaint. Amber collected her thoughts, then sighed. "Well, you already are this deep into it, so I may as well let you in on it. This phone generates a single sentance about a targeted individual. You can change one thing about it, and then it actually makes that change, even if normally it would be impossible for it to happen."
"Right... Let's say I believe you for a second. Can you prove it?" Maddy asked skeptically. It sounded crazy, but it would explain the change in Amber's memory to having to sit and stay like a dog.
"Well, an easy one would be that before I met you, I had a normal sized pussy." Said Amber. Maddy had to agree that it was a pretty solid argument. Her pussy fit around her cock as if it were molded around her every bump, bend, and everything. It was simply too perfect to be real. "That, is incredible."
"I know right? But the downside is that only the current uses knows the change they made. And given your reaction earlier, I bet I never was told to Sit and Stay, right?"
"Obviously, why would I do that? You were nearly passing out from exhaustion and needed a short break."
"Hmm, well that no longer seems to be the case. I feel fine, and likely can go several more rounds with you without it even effecting my breathing. I have some pretty insane endurance." Amber boasted, proudly sticking out her chest. Maddy chuckled at that since Amber looked kind of ridiculous given her current sitting posture.
"Anyways, we can play around with it more later, because I am more than ready for round 4" announced Amber with a grin. Maddy quickly became erect again, grabbed Amber's leash, and walked her back to the bed to continue their long night of fucking.