(Ah... what kind of naughty thing am I doing...!)
While teaching Rest, Viola Rosemary pressed her body closer and felt a mix of excitement and embarrassment inside.
If it were allowed, she felt like rolling on the floor out of sheer shame.
Although Viola appeared calm, pushing her chest against him, she wasn't as composed as she seemed.
She was desperately trying to suppress her embarrassment, fueled by her competitive spirit against her twin sister, Primula.
(Ugh... why is Primula so at ease...? She's so close to a boy our age, and on top of that, she's wearing such a risqué outfit...!)
Viola was wearing a yellow nightgown.
It was something she used as loungewear, not particularly revealing.
However, her recently noticeable cleavage was clearly visible, and the fabric was thin.
It wouldn't be inappropriate among family or other girls, but it was definitely not something to wear in front of boys her age.
(I never intended to wear something like this; it's all Primula's fault...)
Viola had planned to wear a casual dress she usually wore, but her sister Primula had come out in a light blue nightgown.
Viola blushed at her sister's boldness, and Primula smiled triumphantly at her.
Fueled by rivalry, Viola quickly changed into a nightgown of a different color that she had just bought.
"Rest, this problem is easier to understand if you read this reference book!"
"Um... is this okay?"
"Excellent! Wonderful!"
As Rest solved the problem, Primula hugged him while praising him.
Viola immediately felt competitive and pressed herself against him from the other side.
"Great job, Rest! Keep it up!"
(Th-This is so unfair! Primula is usually so quiet, always hiding behind me... Why is she being so forward with Rest-kun!)
To Viola, Primula was her cute little sister.
She was someone she would do anything for, even if it meant risking her own life. She was as dear to her as her own heart.
Though she was supposed to protect her sister, now she stood as a huge rival for a single man.
(H-Have you grown up without me knowing? Or is Rest-kun special? Your chest has grown so much... At this rate, I might lose him!)
The Rosemary sisters were almost identical except for their hair and eye colors and personalities, yet for some reason, Primula's chest size was slightly larger.
Viola had never cared about this before, but now it was bothering her more than ever.
Feeling inferior as a woman only fueled her anxiety.
"Oh, how about this, big sis! Instead of a reward, how about I give you an 'punishment' instead?"
When Rest made a careless mistake on an easy problem, Primula suggested this.
(P-Punishment? W-What is Primula saying!? What is she planning!?)
"That's a great idea! Primula, you're onto something!"
Despite her inner turmoil, Viola said the exact opposite.
Seeing Primula with a sultry expression that belied her fifteen years, her eyes glistening, made it hard for Viola to back down.
"Okay then, punishment. Here we go...!"
"Rest, brace yourself...!"
(W-Wait... what am I doing to a man who's neither my husband nor my boyfriend... Hyaaaaaahhhh!?)
Following her twin sister's lead, Viola reached out to give Rest his punishment.
In reality, Viola was so flustered she felt dizzy, but even so, she let her fingers trail over the body of the man she longed for.