You awaken into a body you barely recognize. All aspects feel wrong, from dimensions to tactility. The sheer wrongness you feel is sobering enough that you're afraid to move this foreign body, much less assess the damages. You hear a voice from behind, where your computer is located.
"Hey, you're awake!" Your first thought is how badly you wish you'd never allowed your sister to see that device. "That only took you...3 hours and 16 minutes, but- I guess you're finished enough." Finished? "Come on, get up! I wanna see what needs tweaking! I did it all by eye, so some of it's probably in need."
You refuse to move, now more than a little out of spite, then raise a hand to your head to feign a headache. "Man, my head hurts, wh -- mmph!" Your hand felt a little heavier than usual, but the true interruption to your train of thought was from the three breasts smothering your face in place of the hand you'd expected. You quickly pull back your limb to look at it. It appears as though your thumb has been reformed into a breast. The other four digits were somehow melded into two more breasts. You flex your "fingers," and are more than a little disturbed when they flop about in response. Each is no larger than a tennis ball, but anchored to your still-unchanged palm they look oversized by comparison to the fingers you once owned. "How did you do this to my hand?!"
You hear laughter from behind you. "Your hand?! That was an easy one. Come on, stand up!" You move your legs just to check there's still something down there, and are slightly relieved to get a response, but more disturbed by the array or other feelings you received from other parts of your lower body as the leg brushed against them. "Look, I'll tell you about all the changes if I can just make sure I've finished you right. As a show of good faith, I'll even tell you the hand thing for free. I started a breast between the two fingers I wanted stuck together, increased the breast size until they were melded in, then reduced it to as small as I could before the fingers started popping back out."
Perhaps that's why you can waggle these digits with some degree of control: they're only a few shades away from returning your actual fingers. Since you're not getting fixed by laying about and you're pretty sure you're still naked, you attempt to sit up, only to find the act much more arduous than you'd expected.
Finally looking down your body, you realize why everything feels wrong. Instead of a chest and stomach, your entire torso seems to have been replaced by a bulbous breast. You no longer have your nautral nipples, and your belly looks freakisly rotund, appearing more as a boob than as a natural gut. You push a hand into your chest and thankfully feel your ribcage, but as your hand traces into your blob-like gut, you can only feel what can be best described as breast-flesh. You hope your organs are somewhere in there, but you're not feeling them with simple prodding.
This chest-breast has somehow pushed your legs into a forcefully splayed potition, creating a large gap that would probably help with breast-balls, if you still had them. "Where're my breastballs?" You curl, nearly using your gut as a pillow as you attempt to reach for where you expect your manhood.
"Oh, I removed them. They were distracting to the final product, but I can add them after you fully appreciate the amount of work I'd managed." You continue searching while still lying on the bed. "Oh, for the love of-I removed your junk, bro. Same process as the fingers, and you'll have a hard time feeling the tiny, recessed boob that holds your stuff with those mittens you've got for hands. Now stand up and walk around!"
"Fine, fine! Sheesh." Now knowing your dimensions a bit better, you heave your body into a sitting position. You look down at your feet to see Sarah had done similar to them as your hands. Your five toes are now 3, with the innermost strangely overized compared to the others. It's nearly three times as large as your other digits so far. What's more, there's a fourth breast precariously positioned between your heel and the floor, and you're pretty sure the poor thing would rupture if you placed your full weight on it. "What the heck's with this boob on my heels?"
"It's to make you walk right - and before you ask, no, that does not mean stand on your heels."
You grumble at how wrong this all is, and lift your body off the bed and try to balance on your toes, but immediately fall forward as your heavy gut pulls forward faster than you'd expected. However, something stops you as you feel a distant tug from behind. You turn to see what could possibly be doing this, and are greeted by a sight that defies all logic. Your sister has a pink tentacle firmly grasped in one hand, with the breastinator plugged into its tip from the other. This tentacle-like breast extends all the way across the bed, anchoring into the flesh of where your rear used to be. You can no longer see the crack of your anus, and this tube of flesh extends from one hip to the other. "What the heck is this?!"
Your sister locks eyes with you. "It was one of the harder breasts to make,"
"Why can't I feel it?!"
She grins. "I may or may not have tweaked around with it a bunch. It's probably still a little numb from all the growing and shrinking." You touch a portion of this "breast" to gauge feeling, and are haunted by distant responses in the back of your mind. "Anyways, I was afraid of this, I didn't counterbalance the two right, so I'm going to need you to stand still and when I ask, tell me if you feel like you're falling forward or backwards."
"...What?! I didn't ask for a five -"
"Six."
"- Six-foot long breast for a butt!"
"You practically asked for it by leaving me with this toy and your defenseless body for hours. So I got bored and tried to make something, like a macaroni sculpture."
"Macaroni? What the heck are you talking about?!"
"Instead of noodles and paper, I was given a boob gun and a brother, who's also a boob in his own way. I know you like a sibling, so just trust me that this'll be awesome if it all works. Now look forward and bend only a little bit forward."
"Kch- Fine!" You do as Sarah asks, and you hear the breastinator activate. After taking a minute to cool down, you decide that all of this doesn't truly matter as long as it can be undone, so you might as well learn your sister's secrets if only to get back at her later. "Why does this butt-breast look so weird?"
"Right! You see, I learned something interesting about this device. Once you start pulling the trigger, it latches in to the flesh. If you allow it, the gun'll try to make a breast just like any other, with that patented separation sort of deal. However, what do you think happens if you force the gun to stay near or far away?" She pauses, but you're sure she doesn't really expect an answer. "Well, when you force it to stay near, you get something like your belly. The breastinator simply doesn't push out past that point, and instead starts widening out. Its why you gut looks like a A-sized breast for a 30 foot tall woman. The opposite is your tail-breast. I made this sucker like 4 times bigger than you, then when I went to 'remove' it, I made sure the breastinator couldn't get closer. It created this weird conical boob that looks practically like a tail!"
You turn to see the breastinator in action, and you really can see what she means. It indeed looks like an breast that was practically sucked dry, but was forced to remain a given length. Then it hit you; a breast that large would would have a massive nipple, and so would the one on your currently-large gut. "What'd you do with the nipples?"
"I shrank the ones that got noticeably large. Turns out the site for this thing had a mod to make the breastinator modify nipples to the point of removal, thankfully. It was kind of weird when your belly had one the size of a small table." She halts the breastinator. "I believe that's enough, now tell me which direction you feel like falling."
She lets go of your less emaciated-looking tail breast, and you fall slightly forward, but otherwise stabilize while on your toes. You take a careful step forward, then start to rotate to face Sarah. However, your tail slaps heavily into the headboard of your bed and the wall, causing you to stop short. "What the heck were you trying to do with all this?"
"What, you've not figured it out? The tail, the toes? While I took some artistic licensing on the final product, the main idea was a raptor, and I'd say it was a success. Especially since I only could use boobs to make one!"