She has one more hole

You both catch your breath, bodies pressed against each other, and it's Sophia's turn to whisper "Wow..." Getting comfortable, she rolls you to your side and turns to face you, smiling. "I take back everything I initially said about the implant. This is amazing." You chuckle in agreement.

The two of you spend a minute together before you speak up. "So what exactly did you change?"

She grins. "Well first of all, you can't get me pregnant right now. That felt like a smart thing to turn off." You nod in agreement. "Secondly, I really love the idea of getting completely plastered with cum. It turns me on so much to be covered and full of it..." She trails off for a moment, looking distracted as she blushes. "So I increased the volume and length of your ejaculations."

"Anything else?" you ask.

She looks back at you with a smile. "One more thing..." She reaches down to tug at your penis and you notice that once again you are feeling completely refreshed, like you could fuck again. You still feel the high from your orgasm, but you don't feel overly sensitive or spent. Your dick hardens. You know exactly what you want next. "You like being full of cum?" you ask.

She blushes. "Yeah, it's so fucking hot."

Your smile deepens. "Well you've only been partly filled." She looks at you in confusion before realization dawns on her. Not giving her a chance to respond, you roll her over onto her chest and position yourself behind her. Sensing your intentions, she lifts her ass up and wiggles it back and forth. You run your fingers along the length of her slit, gathering semen and pussy juice before spreading it around her puckered asshole. Sophia gasps. You spend some time teasing her rim before slowly slipping a finger in, lubricating the inside. Speaking through her moans, she says "Mng, be gentle. My ass is sensiti-" she cuts herself off as you slip another finger in, "...fuck..." You gently work your fingers in and out of her until she starts bucking backwards.

You rise to your knees and place the head of your dick against her asshole. She freezes and shivers. You scoop up some cum to lube your cock before tentatively sliding it into Sophia's ass. She groans deeply in pleasure. "Yes... more..." You press further until her rim is wrapped around the base of your cock. Sophia grabs the sheets with her fists. Slowly, mindful of Sophia's feelings, you start to piston in and out of her asshole. The sensation is incredible. Her tight hole grips your cock, almost sucking you deeper in. You build in speed and she moans raggedly, her breath catching in her throat whenever you thrust into her. You see the phone on the side table and get an idea. Continuing to fuck Sophia's ass, you reach over and pick up the phone. She doesn't notice. You find the setting you're looking for. Sophia had increased the volume of your ejaculations by 100 times. You think to yourself, "If she liked that, then..." and add a 0.

Putting the phone aside, you grab Sophia's hips with both hands and fuck her with a renewed vigor. She howls in pleasure, rocking her ass back onto your cock in rhythm with your thrusts. Intoxicated by the idea of absolutely filling your friend's ass, you sense your next climax building rapidly. You pound her asshole for a few more seconds, grunting louder until you bury your full length with a final thrust. Sophia gasps as she feels your cum start to fill her up. You grab her hips roughly and hold her against you as you cum. Her chest falls forward and you notice she's been playing with her pussy this whole time. You continue to pump semen into her. Around the time when you would usually stop cumming, your orgasm carries on and you moan loudly. In confusion, Sophia looks around and sees the phone missing. Breathlessly, she asks, "Oh my god, did you..." trailing off. You pull her torso towards you so that you're both kneeling, your cock firmly inside Sophia, keeping the cum from leaking out. Through your grunts, you whisper in her ear. "I did. I'm going to fill you up with so much cum you'll be bloated for days. You're my little cumslut now." Sophia's mouth drops open and you **** her face back down into the pillows. Despite her surprise, her fingers continue to work her pussy as she brings herself to another orgasm. The two of you keep cumming together for what feels like an eternity, trapped in your pleasure. You feel your cum continue to stream out of you, filling Sophia's ass, then her intestines. You gently cup her gut and can almost feel it swelling. She moans as her orgasm comes to an end, and shortly after, so does yours.

You both collapse, and as Sophia lands on her belly, your softening dick pops out of her ass. You see a steady stream of thick white cum start to leak out and drip down her thigh. Taking a moment, you both breathe deeply and start to drift off.