Big Brother's Christmas by ImoutoCommissions

Onpu does not seem to have a virus, yet her vomiting continues for about 
a week or two after it begins. It worries you, but she insists that you 
do not need to worry, and do not need to worry anyone else. Mainly, she 
does not want your parents to know about it, which also means that 
seeing a doctor about it is completely off the table. The two of you 
have found that peppermint tea with her breakfast helps to clear up her 
nausea, and she is willing to take that as a treatment, rather than 
seeking any professional help.

After all, if your parents find out, she might be made to take time off 
of work. As she claims it is an important time for her, you decide not 
to say anything about it, just as long as she does not get worse. 
However, this is not the only change the two of you experience.

At night, when she is asleep, she seems to become a bit bolder with what 
she does. Sometimes you are the one to wake up to her already on top of 
you in some way, with her instinctively knowing what awaits her and just 
going for it. Or, at least, that is what you assume is happening, but of 
course, there is no way to ask her about what she does when she is 
asleep. Not only because she would not know, but because that would 
require revealing to her what you have been doing to her.

On some nights, you wake up and she is bouncing on your cock already, 
riding you for all that you are worth, still asleep but clearly loving 
every second of it. Other times, you wake up, and she is grinding down 
against your face, mumbling in a sleepy voice, "Gotta tinkle..." At that 
point, you know to start eating her out thoroughly, to make sure that 
you get her moaning for you, losing herself to her pleasure until she 
finally empties her bladder and lets you drink it all down. No matter 
what, you can't get enough of the taste of her pee, and once you have 
done your part for her, she usually rewards you in the form of blowing 
you.

Your little sister has gotten very good with her mouth, at least while 
she is asleep.

Things mostly stay the same, beyond her morning nausea. You do notice 
her little tummy starting to round out a bit more, and you wonder if you 
have been indulging her too much in her love of crepes. Though you know 
her job means she needs to keep herself in shape, you can't help but 
think that it's not all bad for her to be allowed to enjoy herself and 
her favorite treats every now and then, even if it means putting on a 
little extra weight.

Everything is going very well for the two of you, even if she has no 
idea just how close you have gotten lately. It takes you some time to 
start to figure out what the real problem is, to discover the source of 
her changes and understand your own part in it. It is only once she 
starts collapsing from exhaustion once she gets home every day, falling 
asleep on the couch as soon as she is in the door, that you start to 
realize that there is a lot more going on than meets the eye.

Not only that, but the size of her belly bump has grown to about the 
size of a cantaloupe, and you can no longer pretend this is just a 
strange bout of nausea or an indulgence in crepes or her working too 
hard. All of this is all too connected, and it is connected to the 
carelessness that you have had while fucking your little sister at 
night. When you spoon her and caress her stomach, you know that you are 
not imagining the slight movements, the little flutters in her stomach.

You've put a baby in your own little sister.

At first, all you can feel is shock, and from that point on, you really 
don't know /what/ to feel. You know that you have done something to her 
that should be completely unforgivable, but then, you have been doing 
unforgivable things to her right from the start. This was inevitable, 
and you just tried to ignore it as much as you could, but now, you are 
being faced with the consequences of your actions.

You are so torn as you think through what this means, but the feeling of 
happiness wins out, despite everything. How can you help it? You just 
love her so much, and there are probably thousands of people who wish 
that they could knock up your precious little sister, but you were the 
one to actually do it. No matter how disgusting and depraved the act 
itself may be, you love her too damn much to truly hate yourself for it, 
and you are too happy to be able to have that sort of bond with her, 
whether she knows it or not.

However this plays out, you will just have to see it through to the end, 
taking it day by day and carefully observing her in the process.

~X~

You never see her baby bump during the day. Even when she swaps out her 
usual dress for something a lot more form fitting, she never shows in 
the slightest. More than likely, she does just think that she is gaining 
weight, and is using magic as best as she can to conceal that from the 
world, until she can figure out something to do about it. There is a 
part of you that is tempted to tell her the truth about what is 
happening to her, but no matter how you try to build yourself up for it, 
when it finally comes time to talk to her, you always chicken out. You 
aren't sure how to explain something like that to her, and just can't do 
it.

If her magic can conceal it for the time being, then that takes care of 
that, and in the meantime, you can do what research you can to help take 
care of an expecting mother. All the while, you can make sure to keep 
your parents from finding out what is going on as well, taking the time 
that you need to try and figure out what you can about this. That being 
said, you are still not sure if any level of research can prepare you 
for having to come clean about what you have done, or what to do once it 
gets to a point that even Onpu does not believe that she is just putting 
on a little extra weight.

Time continues to pass without any changes that you are not able to help 
with, and that Onpu is not able to conceal from everyone else. She is 
meant to take part in a Christmas Eve concert, something that wears her 
out so much that she falls asleep in the car on the way home. Onpu looks 
absolutely adorable in her velvety red dress with the white fur trim, 
and countless ribbons to keep it all in place, an absolute Christmas 
vision, one that you were not able to take your eyes off of all night.

Of course, the dress would have exposed her swollen tummy all too 
easily, but as always, her magic managed to keep all of that in check, 
and she made it through the night without incident. However, she falls 
asleep on the way home, clearly exhausted from everything that she has 
done, and when you have to princess carry her inside, you can feel the 
phantom bump there, rubbing her to try and judge what size she must be 
by now. It feels like she is about the size of a soccer ball, and it 
reminds you just how amazing her magic is, that she is able to hide it 
so easily.

And, of course, you can't help getting hard when you feel the bump, 
remembering it was you who put her in this position. You get even more 
excited, remembering that you have her all to yourself. Your parents 
will be busy, and the two of you are going to spend Christmas Eve and 
Christmas itself alone together.

You can't wait to have some fun with your sleeping sister, so you lay 
her in a recliner in the living room, and get to work untying the 
ribbons on her dress. Like this, it really feels like you are unwrapping 
your Christmas present, and that makes the process fun for you, instead 
of feeling drawn out. Finally, you have her down to the opaque white 
body tights that she wore beneath it, covering her and clinging to every 
inch of her body like a second skin.

You wish her magic would wear off right now, so that you could see the 
way it clings to her baby bump. As it turns out, though, you do not have 
to wait all that long for your wish to come true. You soon get to work, 
peppering her with kisses all over, covering her face and her neck, 
before moving on to her chest, which has started to develop a bit, due 
to her pregnancy. While you are doing this, the tights begin to move, 
stretching as her bump grows visible again, forced to conform to the new 
shape.

You move down immediately to start kissing her there, unable to help how 
excited you get in the moment. Once you have kissed all over her 
adorable tummy, you move down her tights to find the slit you can pull 
open, made into the tights to allow her to go to the bathroom without 
having to fully undress. Like this, you can eat her out without ever 
taking it off, loving just how delicious she tastes to you. She may not 
know how worked up she is for her own big brother, but you do, and it 
means the world to you that you are able to get this sort of reaction 
out of her.

Once done with that, you lift her out of the chair so that you can take 
a seat instead, and can pull her down onto your lap. Pushing up into 
her, you fill her completely, and set a slow pace as you begin to fuck 
her, rubbing her tummy all the while. It feels so good to be inside of 
her, and you take your time with it, wanting to enjoy it as much as you 
can. However, once you do start nearing your climax, Onpu begins to 
squirm, mumbling in her sleep, "Need to tinkle..."

With that, you stand up, still buried inside of her, and carry her to 
the nearest bathroom so that you can hold her over the toilet. Just in 
time for her to give in as well, and while she pees for you, you hilt 
yourself within her and fill her cunny with your cream. Once that is 
done, you decide you should give her a bath. Just because she is too 
tired to get cleaned up does not mean you can't do so for her while she 
is out.

You strip her down to nothing and are careful as you fill the tub, 
making sure it stays a temperature safe for pregnant mothers. You then 
ease into the water, keeping her nestled in your lap as you do. Onpu is 
still completely out, not showing any signs of waking.

While you are washing her, she starts to grind her butt against you, 
clearly getting impatient due to the habits she has developed solely 
while asleep. Eventually, she goes for what she wants, lifting herself 
so that she can drop down onto your cock, whimpering as you fill her. Of 
course, you can't help but lose yourself in it as she rides you, moving 
rhythmically until she has pushed you to the edge again. You fill her 
with another shot of your seed, and it really is no wonder she ended up 
pregnant, all things considered.

You soon finish bathing her and getting her dried off, before carrying 
her to your bed. She is more than likely going to end up there before 
the night is over anyway, so better to just let her rest here. You then 
go to clean up her discarded clothes from the living room, take them to 
her bedroom, and get a warm nightgown, one that is still loose enough to 
accommodate her baby bump.

When you return to your room, you walk in on Onpu laying with her face 
to the bed and ass in the air, legs spread in a way that both shows off 
her pussy and her baby bump. Like hell you can resist a temptation like 
that, wondering how she got to be the perfect seductress strictly 
through sleepwalking. You are soon in position behind her, grabbing her 
hips and holding her up to make sure that she is not putting any 
pressure on her unborn child, before pressing your cock against her 
waiting pussy and pushing in.

After all that you have done so far, you really do not have any 
endurance left in you, and so, it does not take long before you have 
worked yourself into a frenzy, finishing inside of her once again. At 
that point, you are completely exhausted from going three rounds with 
her. You move her onto her side as you snuggle up behind her, deciding 
that you can get a quick nap in, before enjoying the rest of your night 
together.

Pulling the blanket up over the two of you, you snuggle in closer, soon 
falling asleep like this, cock still buried inside of her.

~X~

The sound that wakes you up in the morning is the voice of your little 
sister, sleepily whining, "Onii-chan, I need to pee..."

You jolt awake immediately, realizing from the sound of her voice that 
she is not still asleep, that both of you are naked, and that you are 
still balls deep inside of her. Not only that, but you're getting harder 
by the second, morning wood waking up as well. You must have been more 
tired than you realized, and slept through the whole night. Not only did 
you waste that night with Onpu, but you also have ruined everything, 
allowing her to catch you in the act.

"I'm going to wet the bed if you don't let go of..." she starts to 
mumble, still not realizing that you are doing a lot more than just 
holding her. However, she trails off, as realization fully hits her and 
she recognizes not only your shared nudity, but also the fact that her 
illusions have failed, and that there is something hard and thick buried 
in her girlhood.

Her face soon turns a deep shade of red as she stammers, "Is that...is 
that your...your thing...is it in my...my special place?!"

What else can you do now? You have been caught in the act, due to your 
own slip up, and you have known for a while that you needed to come 
clean. After all, she has ended up in a situation that she can't exactly 
ignore forever, and eventually, the truth was going to come out. You 
would have preferred to tell her under more favorable circumstances, but 
considering the fact that you were never able to find such circumstances 
before, it seems this is all you get.

So the truth all comes spilling out of you then, as you tell her 
everything that you can about what you have done to her. You try and 
soften things up a little bit, so that she can understand, but you do 
not lie to her. By the end, you are rubbing her tummy, saying, "And it's 
because of me that you have a baby growing inside of you. I could tell 
that you were because your magic wears off at night. And, yes, I'm aware 
of...all of that."

You are careful with how you say it, so that you do not put her at any 
risk with your words. If you are going to tell the truth about 
everything, you might as well be honest about that as well. You finish 
it all with, "I don't know what we'll do when the baby comes, but I'll 
do whatever I can to help you hide your pregnancy."

It takes Onpu time to process what you have told her, and in that time, 
you are fully expecting a kick to the balls, a punch to the stomach, or 
at least a slap to the face. Instead, she takes you by complete 
surprise, finally moving to steal a quick kiss from you. Her face is 
still red as she says, "I've...I've had a crush on you for a while...and 
I've been having dreams where you play with me in weird ways for months. 
I always liked them, and I thought it was just because I liked you that 
I had them."

You are stunned by her words, but you know that this is a good thing, 
that this means the two of you have even more of a future than you ever 
could have dreamed. She goes on to say, "I'm still not sure what to 
think about...having a baby, but I'm at least glad to know I'm not 
getting fat. I couldn't figure out what I was doing wrong, so I'm glad I 
can just keep using illusions for a little while, and then maybe get it 
back to normal?"

"And I'll be there with you the whole time," you assure her. "I love 
you, more than anything."

She looks ready to return the sentiment, but the moment is spoiled as 
she suddenly winces and cries out, "I need to go pee right now!" At that 
point, your top priority is getting her out of bed and carrying her to 
the bathroom, holding her over the toilet just in time.