This is just a bit of scribbling I did for fun.
It has no bearing on the story.

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My name is Lucas of Epperin, the second child of Theodore and Paula of Epperin.
As my father's first-born son I'm currently working as an apprentice to prepare myself as the heir to the Epperin Trading Company, though I'm still inexperienced and tend to screw up a lot. Luckily my big sister is always there to cheer me up when I'm down after making a mistake.

I admire her a lot and since she's much smarter than me I think she's better suited to inherit the company, but since a girl can't be the head of a noble household I have to do my best to do a good job in her stead!

A few months ago Mom told us that we would be getting a new sibling and since then her stomach has grown a lot, so I've been very excited recently.
I wonder if it's going to be a boy or a girl?
No matter which it is, I always wanted to be a big brother and now that dream can finally come true!
Hopefully I'll be as reliable a sibling as Big Sis.

Since Mom became pregnant she and Dad seem very happy together, even more so than usual. They're always going on dates and dad is even sometimes cancelling meetings with representatives of other companies to spend more time with her and the baby.

It was during one of those dates, when Mom and Dad were out in the city until late at night, that I saw my sister sneaking into our parents bedroom upstairs. She had just returned from a long day of work as a guild scribe's apprentice and was still wearing her baggy blue uniform with a red ribbon on her chest and the big round glasses she needed because of her near-sightedness.
I was taking a break from my studies and her suspicious behavior made me curious what she could be doing up there so I followed her without making a sound. The door was left ajar, probably because she didn't want it to make a sound when shutting, so I was able to spy through the gap without a problem.

My beloved big sister was bending over, facing away from the door, with her dark brown hair that was braided into a loose ponytail hanging down to her side.

It looked like she was searching for something in the lowest drawer of Dad's night stand.
After a short while she seemed to have found what she was looking for as she dropped a small bluish glittering object on the neatly arranged sheets and started walking towards the bottom side of the bed before pulling down her pleated blue skirt together with her panties.

She was still facing away from me so her bare butt and crotch were completely exposed as she bent down once again to remove the clothes from her lower body. My eyes were fully fixated on her slit that seemed to be wet with some kind of liquid as I felt my penis getting hard.

I had stopped bathing with my big sis about a year ago, since I became increasingly embarrassed when seeing her breasts that were growing bigger and bigger, so I didn't noticed how the dark hair above her mound had increased a lot recently. She really looked like an adult like this.

After taking off her panties, she sat down to the side, leaning against the bed while still wearing her loose blue top that was nevertheless betraying the shape of her large chest.
From my position behind the door to her right I could now only observe her from the side.
Having gotten comfortable, she spread her legs and began slowly pushing the index and middle fingers of her right hand into her vagina.

"Nhh..."
A jolt ran through my body.
I had never heard my sister make a sound like this, but I knew I wanted more of it.
A strong urge to touch my dick came over me, but I continued watching without moving my hands.

Her left hand reached on top of the bed behind her, for the light-blue crystal that was about double in length as it was it was wide.

I knew what kind of crystal this was since I had learned about it during my training as merchant apprentice.
My sister was holding a memory crystal.
These crystals are enchanted to start recording everything around them when mana is supplied by a user. They only stop once the mana that was inserted is used up or the user makes a predetermined gesture, most of the time a simple snap of their fingers.
They can only be used to record once, so they're quite expensive, but once they have a recording inside anyone who closes their eyes while touching the crystal will see and hear the events that happened at that time, almost as if they had been there.

As she grabbed the crystal with her arm extended backwards, my big sister began quickly moving her fingers in and out of her pussy, filling the room with increadibly lewd slopping noises.
"Aahhhnnn... Nhhh... hhNnnn...."
-slup- -slup- -slop- -slop-

That was when I couldn't take it any more. I had to look at properly. I wanted to get a close-up view of her pussy as it was relentlessly tortured by her own fingers.
I gulped.
While viewing the recording of a memory crystal one could only hear the sounds produced by the crystal, at least that's what my teacher told me.
I purposefully knocked my knuckle against the door to see if she would have any reaction.

"Nhhhaa.... Nhhhhhh... Haaahhhn..."
-slop- -slop- -slop-

Nothing. She continued as she did before, not acknowledging the sound at all.
I pluck up my courage and open the door, approaching my big sister who was masturbating in front of me while being naked from the waist down.

I positioned in front of her , getting on my knees and moving my face right in front of her crotch as she was squirming and moaning while the liquid from between her legs sprayed on my face and down on the flood beneath.
Her head was thrown back, resting on top of the bed and her eyes were closed while facing the ceiling. Right now, even if she opened her eyes, she wouldn't see me right away.

"HhhaaaaHhnn... Nahha...Nhhhhh..."
-slip- -slop- -slop- -slop-
She continued moaning, the skin of her baby making hole sticking to her fingers as they moved faster and faster.

I pulled down my pants. My erect dick now fully exposed in front of my beloved big sister and I began stroking while looking at her masturbating in front of me.

Both of us continued like this for a while before I felt something welling up inside of me and suddenly a cloudy white liquid squirted out from my penis, hitting the floor between her legs right in front of her crotch.
-splurt-

I had felt like this before when stroking my dick while thinking about my big sis, but this was the first time something came out of there that wasn't pee.

Suddenly, my sister inhaled through the nose as if she was smelling something strange before stopping her fingers.

In a panic, I pulled up my pants and ran out of the room before she could decide to open her eyes and see me.

...

I breathed heavily as I lied on the bed in my room.

I hope she didn't notice me... but more than that... I wonder what was recorded in that crystal?

End Chapter 4.6