"Ok, but at one condition"

-What is it?- You frown at Tina's devious smirk.

-Let's spend a day inside of them!- She announces enthusiastically. You, instead, groan, discouraged: for some irrational reason, you thought it would have been easier. But it was hopeless, wasn't it? In the end, it's of yourself you were talking about: that is, yourself having access to your little sister's delectable body. For the first time, you feel like you're truly disgusted by yourself.

-I don't know dude. It feels wrong.-.

-Oh, brush it off! You said so yourself, well you were meaning it, that it's right to have some fun. Just another 24 hours, and then... then we will do as you say, promise.-.

She's lying. Or better, she's avoiding saying something, you can sense it; and you know that you should point it out. But... but you can't deny that the offer is tempting. Another day inside Kim's body, this body! You've been in there only since last evening, and you can affirm that it was the best night of your life. Her body is so, how to say it, so fragrant, so refreshing, almost intoxicating; after all, you were planning to stay inside of it on a permanent basis. Sure, you had the will to communicate your resolution, but it's not like you're facing a straight rejection for which you could have strengthened your position; on the contrary, this compromise is alluring, a perfect win-win scenario.

And so your disgust yields to the temptation.

-Fine.- You eventually say. Tina rejoices with a "yes" loudly whispered, and with a fist in the air.

-But no trick. No jokes. And, definitely, no more...-.

Words die in your throat, and an equal look of dismay crosses Tina's pretty face.

-Oh shit, the goo!-.

You rush into the kitchen as if you have the devil at your heels. You quickly scan the environment to evaluate the situation: Tom, that is your original body, has finished his breakfast and is getting up, while your mom is throwing the fragments of the cup into the bin, bent forward and showing you the full and bewitching shape of her firm butt. And, right behind her, crawling on the floor from the puddle of coffee...

"Fuck! He's going to jump on her! And Tom is gonna see it! What do we d...".

-Sorry sis.- You hear the murmur, and then you are pushed forward towards the table right when Tom is circling around it. You see his shocked face just before clashing against him, and you almost tip over on the table.

-Woah, woah!- Someway, he spins on himself as in a pirouette, dissipating your kinetic energy in the rotatory motion. All of this, of course, holding you tightly by the shoulders, with his chest pressed to yours.

Oh God. Have you always been this big?

You move your astonished eyes from him to your sister, fearing that she has tried to betray you. Instead, you soon realize she has used you as a diversion, since she's laying on the floor, right at one centimeter from your mother, her hand joined in a squeeze. The woman, stunned by all that noise, is shifting her shocked gaze among her children.

-What's happened? Tina, what are you doing?-.

-I, uh...- She babbles as she gets on her feet: -I just found a, I mean, there was...- Your mom's eyes fall on her hands, and terror paints on your sister's face.

There is only one thing you can do. You instinctively emit a loud "Ohh" and you lurch back theatrically, diverting Tom's attention from the scene and forcing him to lean forward in order to hold you again. Mom too turns to you, and at that moment Tina slips her hands into her mouth, gulping down and shuddering in distaste. But at least it's over.

You feel you can breathe a sigh of relief; but then, as you meet your old eyes, time freezes, and your heart skips a beat.

THUMP

You realize that your "brother" is holding you like in a casque, his hands tightly grasping behind your back, his breath distant from your lips much less than the length of the hair which is hanging, almost vertical, from your head; and, even if your pelvises are not touching, you can almost sense, or to better say it your pussy can almost sense, an erected member pointing at her, and it's so damn close; yet, something in you is saying, not enough too.

He's petrified too, and the more you feel his sight upon you, the more you feel your cheeks blushing and your body burning hot. Until you have a moment of clarity, and following the impulse you slap his face with a loud noise that echoes in the room. Tom whines, perhaps more pained in the soul than in the body, and with a leap you get straight back.

-Kim, honey, are you ok?- Your mother asks, deeply worried by the scene you caused.

-I don't understand...- Your body complains, rubbing his cheek.

-W-What's got into your head, uh?- You blurt, words are coming out on their own, while your heart still drumming and you still don't know why.

"What's happening to me??".

-Just because I lost balance, it doesn't mean you can get any strange ideas!- You hear yourself saying.

-But I didn't...-.

-Shut up!-.

He jerks and lowers his head, feeling brought back in line. Your mother instead must be so floored that is now reacting mindlessly at every input she detects, and thus she turns around when she hears Tina moving.

-Here, you were missing a piece, yep...- She tries to sound casual, having bent over the bin.

Mom opens and closes her mouth a few times, then says: -...Guys, are you sure everything is alright? If you're feeling sick or if there's anything that is bothering you, you know you can tell me, at every moment.-.

The concern in her voice pinches straight in your chest, and for a second you are overcome with deep remorse: she's worried for you, and yet you are lying to her so blatantly, pretending to be her daughter and even having attempted to transform her into... into God knows what you are.

-Yes Mum. Tina and I are just a bit tired, that's all.- You lie.

-Are you sure? Oh, girls, how many times do I have to tell you not to stay up late?- She scolds you lovingly as she always does in these cases; however, if you think back at the reason for this specific one, you feel the desire reignites between your legs, spreading its heath along your guts. But, now that you notice, you also feel another stimulus, similar but somehow unpleasant, which you fatigue to recognize being slightly different from the one you're used to.

-Y-You're right, as always. Come on Tina, let's go upstairs.-.

-Sure du...erm, dear sister!- You hurry away, leaving your two perplexed family members wondering what has gone into you. If only they could imagine how literal the answer would be...

You groan, struggling to relax the correct muscles nearby your slit, muscles that are likewise new to you. Finally, a warm flow springs out from the little hole over it, sprinkling the porcelain bowl you're sitting on. Having your eyes closed, you can focus on the sensation of your bladder gradually emptying, non dissimilarly from your original one; yet, what is truly weird is the arousal that accompanies the best-known sense of alleviation, as much as having the peeing hole right in the middle of your thighs and attached to your hip bone. Maybe, you reason, the two things are linked. The female body is still a mystery to you.

When you've finished, you reopen your eyes and take an exasperated sigh.

-Happy?-.

-Yup.- Says Tina, who gets up from being crouched in front of you. You clean yourself with toilet paper, fuck that's strange too, and finally put on panties and shorts again. When you turn around to flush the toilet, your vision lingers on the yellow substance on the bottom, developing a strange fixation. That wasn't yours, you think, but it came out of you. Even more, it was your sister who filled the bladder, but it has been you who emptied it, who used the inner parts of her body for the expulsion, who stole her of the sensation. Of the choice.

"Better not to think about it".

-So...- Tina looks at you, a subtle smile on her lips.

-What was that, before?-.

-Uh, what are you talking about?- You play dumb.

-Oh, come on!- She knowingly enlarges her grin: -I've seen how you were looking at our beloved brother while he was holding you tightly in his virile arms...-.

-I, no, you're wrong, I wasn't... it was just a scene.- You splutter, but your body language reveals a very different truth, as you divert your eyes to the floor and you squeeze your shoulders with your hands.

-But we both know it wasn't only that, was it?- In a low blow, Tina approaches you, her body is attached to yours, her lips are right in front of yours. You have just to look up, and that would be enough to...

A shiver runs down your spine. No, not yours, Kim's spine. Kim's shiver. Kim's neurons. Kim's excitement.

"Oh God...".

-I know that last night you had a moment...- She entices you with a whisper.

-A moment when you asked yourself... when you dreamed... when you felt that that emptiness could be filled... had to be filled...-.

-N...No...-.

-Yes, you did. Because... I... did it... too...~-.

Her delectable fingers lift, caressing it, your chin. Tina's piercing blue eyes dagger your sight, your sister's breath intoxicated your nose. Your lips meet once again, like before, outside the kitchen; but, this time, the kiss is slower, more savored, more aware. More delicious.

Tina's hand moves upward along your leg. You know what she wants, and you know that she will obtain it. You have to stop her before it's too late.

-Wait.-.

Kiss.

-Wait.- Your digits find hers, and you hold her hand on your tight, to her displeasure; and, you have to have to admit, not just hers.

-That's not part of the agreement.- You say with a lump in your throat.

-It's just... just a bit of fun...~-.

-No. W-We have to stop.- You state, and God knows how it's excruciating. But Tina finally gets it, and she departs puffing.

-Spoilsport.- She pouts.

-Yeah. Well, I'm going back to my, that is, Kim's room.-.

Your attempt to cut it off is nullified by your sister's outreached arm on your shoulder.

-Hold on, at least we get to live the day as they would!-.

You would like to reply something, but if you plan not to ruin Kim's life that's probably the best thing to do. And, gosh, just the thought is making you so wet...

-...Fine. Besides, what will they ever have to do today?-.

The way Tina grins, you understand she was prepared for that question, and you finally understand what she was hiding from you.

-Why, don't you remember? They were planning to...-.