Little miss Mackenzie is a cool kid who does drugs. You are babysitter/older sister/cool big friend she does drugs with. One day she offers the most dangerous addictive drug of them all to you.

Today you were hanging out with the coolest “elementary schooler” you knew, Lil Miss Mackenzie. She had big round pink glasses, braces, two skunk ears, and cute lil pigtails all of which made your head spin for reasons you didn't like to think about. It was a bit odd for someone of your age to be hanging out with someone so young, but she did drugs with you and played old games for you and what was the harm in that? Well aside from a kid doing drugs but well that just made her cooler in your eyes. 

Kenzie had a way of teasing you about things though. The age difference, the fact that you spent most of your free time as an adult with a grade schooler, the way she made your face blush when she sat in your lap and leaned back to look up at you after making a silly pun and smiling a big braces filled smile. The way your heart raced when she got all tuckered out and crawled into your lap-

Best not to think too much about that. You shake your head and slap your face to get a hold of yourself. Today she said she had a new drug, one she had been doing a lot. You were looking forward to it eagerly through your whole day at work.

When you got to her house however, you weren't so sure. She was in a slightly oversized T-shirt you had given her and her nighttime pull ups. She was sucking on a pacifier and looked very blissful, but she popped it out when you came into her room.

"Heyyyyy!" She said in a slightly dazed tone, but she seemed to be coming too. 

"What's up?" You ask, taking a glance at her pullups, they were wet. You knew she had 'accidents' on occasion, but this seemed intentional. An effect of the drug? You wonder.

"Oh you know, just chilling, hehehehehe." Kenzie's giggle was mischievous. 

You chuckle nervously back at her, and ask the question. "So uh, what's the new drug?"

Kenzie smiles her big braces filled smile that always makes you blush as she proffers the pacifier still wet with her drool. "It's age regression."

"Wha…?" You say confused.

"Well I mean you're always hanging out with me, but you're sooo much older right? I figured we could have more fun if you were a little younger~" Kenzie smiled. There she goes again, teasing you for hanging out with a kid.

"Look Kenzie-" You began to refuse, but she cuts you off.

"C'moooonnnnnnnn. What are you scared of? You're a big girl right? Just one suck." She waved the pacifier in front of you. "You'll totally be able to quit if you're a big girl, right?" She was closer to you now, that and her smile were overwhelming your mind, shutting down the voice that wanted to tell her no. You relent.

"Ok… just a little…" You take the pacifier and place it in your mouth. Kenzie's saliva mixes with yours and you can't help but feel your heart rush at the thought. She takes you by the hand and sits you down where you usually watch her play games together. The effects are a lot like weed, you think. Just a sort of fuzzy feeling, a bit of cognitive impairment, unaware of the passage of time. In fact you see Mackenzie loading a bowl in your lap, but you weren't too concerned about mixing drugs. You suck on the pacifier, your head spins.

Was the room always this big? The thought came to you after a long period of not thinking. Kenzie was well into the process of hot boxing her room, so you didn't even have to take a hit to also start feeling the effects of the weed, but somehow it felt stronger. You couldn't quite put your finger on it, you sucked on the pacifier more. It was calming. Kenzie giggled at you.

"Someone's enjoying herself~" She said in that teasing voice. You look down to where she's pointing. A wet spot had formed on the floor beneath you without you noticing, and it took an even more embarrassing amount of time for you to realize it was growing because of you. You were pissing yourself and you didn't even realize it! In a panic you look towards Kenzie for help, but she was on top of it with a towel and a diaper.

"Mom usually puts these on for me, but I'll do you just this once. It's your first time after all~" You aren't sure how she does it but in no time you're in a T-shirt and diapers just like her. The mess on the floor is cleaned, and now you're back to watching her game sitting on a padded butt. She feels much larger in your lap, and you feel much less able to control yourself in more ways than just continence. She half gasps and half giggles as you put your arms around her.

"Jeez, what are you some kind of horny teenager?" She teases, pausing her game. The part of you that knows it's wrong doesn't seem to be there as your hands wander up and down her chest and tummy. 

"Well I guess that's about right for you huh you big perv~ Big sis taking advantage of her little sister while on drugs?" Kenzie teases as she leans into you. Damn her it's just the opposite, you think as your hands find their way under her shirt brushing against her smooth fur. Suddenly like a switch being flipped you're nervous, in a rush of horniness combined with the mental fog of the pacifier and the weed you were now fondling your bestfriend who was also a grade schooler. You freeze, caught in the headlights stare of Kenzie looking up at you, smiling a more coy smile this time.

"No rush, big girl." She winked. Oh she knew, this whole time. Your face flushes and you remove your hands from her to cover it. Kenzie just giggles, but then a small hand reaches out to caress the back of your head. 

"We can just chill too, like we always do." She says. You remove your hands and two big tears roll down your cheeks. She knows and she's ok with it. You think. Well she had always teased you about it but until now it was all just fun and games. Maybe it's the weed, maybe it's the pacifier, but you lean down and give her a big kiss on the lips. You feel flustered, exhilarated, like you were a teenager experiencing her first kiss again. You suppose in a way you were, in body at least. One with big bladder issues. In the silence after you can hear the hiss and splatter of your diaper being filled. Kenzie starts laughing, and to your surprise so do you.

The night continues as it normally does for you and her. The differences are subtle, but noticeable. You chatter more, you get more excited about things happening in the video game, you giggle lots with her. She leans a bit more into you, her diaper rubs a little closer to your crotch, she's still teasing you as she loves to do, but it's ok right? Like this it's ok…

The next day you were eager to get back to her place and even more eager to get started. Kenzie shared a bowl with you and you felt yourself getting smaller before even putting the pacifier in your mouth. You passed it back and forth with her like it was a joint, swapping spit each time and giggling about it. This time you brought a game to show her. 

"I loved this game as a teen." You stated, booting up the PlayStation 2 to the classic startup noise.

"Yeah I bet you do." Kenzie snarked. She wouldn't let the opportunity pass. She had been teasing you about enjoying the age regression ever since yesterday. 

"Shut up." You say with a grin. "Little brat." You add on a whim. You've never bantered like this before, and you both snickered like hyenas. Showing her an old passion of yours felt exhilarating, you were way into it, and like her excitement when she showed you an old game she loved, it was infectious. You could hardly keep your hands off each other long enough to actually play the game. 

Kenzie readied another bowl in the bong and grabbed your face, blowing her inhaled smoke back into your mouth, her little tongue exploring just a bit into yours. This sent you into stunlock, causing you to die in game. Oh she laughed at you for that. Well how about a little payback?

You were still bigger than her after all. You took the giggling girl and gave her a kiss of your own, after all if she's gonna tease so much she must want it right? You pin her to the floor and really explore her mouth with your tongue, running it over her braces and nibbling her lips. She returns the favor, and soon you forget why you were doing this in the first place, lost in the sensation of kissing Lil Kenzie.

Once again you're interrupted by the sound of wet diaper expanding and you're somewhat brought back to your senses. Before you start to panic Kenzie pushes the pacifier between your lips and you start to suck, relaxing. Why did you care about pissing yourself again? Well you were supposed to be a big girl… right? It was hard to remember, hard to think. Much easier to just suck on the pacifier and relax. Kenzie took over the games for the night and you held her from behind, the soft 'nuk nuk' of the pacifier the only noise you make for the rest of the night.

It wasn't that you had a problem, you thought, as you hurried to the bathroom at work. It wasn't much, just a little dribble, and you caught yourself right away… At least that's what you told yourself. You had been zoning out, thinking about tonight with Kenzie, and by luck your coworker asked you a question right as you started to pee. You couldn't regress while at work, that would be bad, but you longed too. You longed for the safe feeling of the pacifier, the fuzzy mind, Kenzie's soft lips…

You were daydreaming again. At least this time on the toilet with your pants down. You quickly cleaned up and got back to your shift. The whole time the call of the void beckoned. Better not drink too much water either. You thought.

Kenzie was waiting for you, diaper in one hand and pacifier in the other. "Back for more, big girl~" She cooed in a mocking tone. 

You were, you wanted more very badly, but maybe for the sake of the rest of your life and responsibilities you shouldn't. "Listen Kenzie…" You began, just like before. You tried to find the words but you couldn't take your eyes off the diaper or the pacifier. Maybe just one more night wouldn't hurt? You hadn't even been sleeping in your own apartment, just passing out on the floor here at some unknown time.

Your will broke, it was like the age regressed you was the real you now, and you had to try to be the old you. In a poof of smoke you found yourself again in your teenage body, maybe even pre teen now? With a huff you said "Gimme those." As you grabbed the diaper and shoved the pacifier in your mouth. With a few quick adjustments you had it on and once again on the floor staring at Kenzie's ceiling decorations, giggling to yourself.

"Well so much for being a big girl huh." Kenzie plopped down next to you with a plastic diaper squish as she lit the bong and pulled. "You want snacks? Mom's got gogurt downstairs." She asked, only coughing a little.

You nod, a little nonverbal at the moment. She hands you the bong and goes downstairs to retrieve the snacks. Idly you take a hit as you think about what's going on. It's like your age was an elastic band, before it had been stretched along normally like everyone else until you unhooked it. Now it was hard to stretch it back out to where it was before. It was like the peg for your real age broke and now to keep it there you had to hold it by hand. Even if you stopped now would it make a difference? 

Kenzie had always seemed to have this knowing look at you. Turns out she knew you were into her, and now this? All this thinking seemed to distract you enough to let go unconsciously, releasing the days drink as piss into the waiting diaper. You sigh, it felt good. Everything about this felt good. Was that so wrong? No, but something was still bugging you 

Kenzie returned with the gogurts which you took and sucked on while she took another hit. "Fuck it." You said aloud. 

"Huhwha-" Kenzie managed to get out before you were on top of her again. 

"I may not be as big as I was, but I'll show you I'm still the big girl in these parts." You said, pinning her to the ground, enjoying watching her squirm underneath you. You straddled her hips and squished your diaper on top of hers, grinding against her like you've always wanted to do.

Kenzie whimpered under your assault. Your hands were back under her shirt, feeling every part of her you've always wanted to feel. You listened to the noises she made as your hands brushed across her flat chest. You lowered your head to her neck and shoulders and kissed and licked and nibbled on her. You moved over to her mouth and again kissed her deeply, only coming back up for air once her squirming got too much. You both breathed heavily, panting as a line of drool from your tongue spilled into her mouth.

And then, satisfied you've reasserted yourself aas the older one, you stuck the pacifier back in her mouth. You picked her up and placed her in her spot on your lap. Your chin rested on her head, arms wrapped around her. With a certain satisfaction you could hear her peeing as she sucked on the pacifier. That's better. You thought. You might not be a big girl anymore, but at least you could still be the bigger sister. You could live with that, you smiled, looking down at the sweet head of Kenzie and giving it a kiss. 

"You're a good girl Kenzie." You say.

"Phank yew biwg sis…" Kenzie manages from behind the pacifier.

"Thank you, for all this!" You snuggle up close, wrapping as much of yourself as you could around her. You've never been happier.