I was not sure what happened, but there was a slight change in Ryuz's mood.
It was a bit hard to explain directly what changed.
If I had to say, maybe she became more proactive?
Beyond just a simple rivalry with her sister, she seemed to be trying to catch my eye.
"Teacher~ That erotic book you were reading… Can I see it, too? It's okay, right?"
Today, she was lying on my bed, flipping through that erotic book.
A top-tier beauty lying in my room, reading an erotic book.
Such a luxury would have been unimaginable in the past.
Above all, it was quite entertaining to watch.
'Really, her breasts are no joke, no matter how many times I see them.'
I might not know about her overall style, but if we're talking just about breast size, Ryuz was definitely bigger than her sister Lorein.
Not that Lorein's were small, but Ryuz's were just exceptionally large for her height.
For reference, Ryuz was wearing a revealing white tank top and hot pants, showing off her broad shoulders.
Almost like underwear, her bold attire was eye-catching.
Her large cleavage and pale thighs were exposed as if to flaunt them.
'It's almost like she's asking to be devoured with that outfit.'
Her true intentions probably weren't much different.
Otherwise, why would she be reading an erotic book in the room of a man she had sex with?
It's as if she came just to show off her body.
So, I blatantly stared at her full breasts and apple-shaped hips.
'Wow, what a killer body.'
The combination of her slightly pressed breasts and her tempting hips while lying down.
Considering her young age, her figure was criminally seductive.
As I was enjoying this arousing view, Ryuz suddenly turned her head towards me.
"....Pervert~"
Then, with a playful smile, she slightly lifted her hips as if to show them off.
The area between her thighs and her private parts was incredibly arousing.
Her cheeks were slightly flushed, and her exposed body oozed sexiness.
This was outright seduction.
"... You've been staring all this time. Your lewd gaze is pricking your student's sensitive skin~"
She had grown up enough to even provoke like this.
Her blushing cheeks still showed her effort to act mature.
That made her look even cuter.
"And I've been studying with this erotic book all this while..."
"What kind of study do you do with an erotic book?"
"Of course, finding ways to please you, Teacher!"
Oh, her words were quite arousing.
Whether she knew what was about to happen or not.
Ryuz tapped the erotic book with her palm.
"No matter what, everyone in this book is just too lewd. Don't you think your taste is too perverted, Teacher?"
"... That's normal for a man, I think."
"In this book, women suck men's dicks and even rub them with their breasts?"
"Men are like that. They all wish for a woman to suck their dick and rub it with her breasts."
I was confident that 99 out of 100 men would answer the same.
The remaining one probably fell victim to some transformation and became a female.
"Huh, huh~ So you've been looking at me with that kind of gaze during every lesson."
"I've been doing that since I first saw you. Ryuz is pretty and has a great body."
"W-Wait a minute… It's unfair to come at me so directly like that…♥"
Ryuz gasped for air, hands on her large breasts.
Typical of Ryuz, getting aroused easily by compliments.
'She knows nothing about men, yet she's earnestly studying because of me. Kind of cute.'
Ryuz seemed fascinated by the sexual knowledge she gained from the book.
It was the age when interest in such matters was natural.
Since she had only recently awakened to sexual desires, her reactions were understandable.
A woman who had discovered pleasure often couldn't control herself.
"Hmm… Do men feel good just by being touched or rubbed without penetration?"
"Of course, it's nice. Especially when a woman you love is serving you."
"Huh~"
Ryuz's eyes turned towards me, more precisely, towards my lower half.
My erection was noticeable even through my pants.
"So, Teacher, you like that too? Seeing how erect you are already."
"It's because Ryuz's breasts are so big and beautiful."
"Ah~♥"
Ryuz's shoulders twitched.
Now, even a simple compliment like this made her react.
Her lower half, clad in hot pants, twitched slightly.
She seemed ready, probably turned on just from the earlier compliments.
"...Looking at this book, you really like big breasts, don't you, Teacher?"
"Well, yeah. No reason to prefer small ones."
The softness and firmness of a breast that couldn't be fully grasped by hand.
There was a kind of magic in them that drew out a man's sexual desire.
"....Would you like to touch your student's breasts?"
Ryuz seductively slid down the strap of her tank top.
Her breasts were so large that even this slight movement made the flesh wrapped in her lacy black bra jiggle.
A bra that was clearly chosen for the purpose of pleasing a man and for sex.
Ryuz fondled her own breasts over the bra.
"My breasts are big and soft…♥ You'll surely feel good if you touch them…♥"
Ryuz looked at me with a suggestive smile.
She even flirtatiously fluttered the fabric near her chest, a trick learned from the book.
Sitting still when my student was going this far wouldn't be polite.
I immediately approached and first removed Ryuz's bra.
Bounce!
Her elastic breasts, confined in the tight bra, sprung out vigorously.
Pale breasts that boasted attractive pink inverted nipples.
Her breasts, larger than her head, shook immensely, almost unrealistically.
"Hehe…♥ Now you're really undressing me without hesitation."
"Did you dislike it?"
"No, it's very manly and cool~"
"Ryuz's breasts are very feminine and beautiful, too."
As I stroked her head and complimented her, Ryuz's cheeks turned red.
A mix of embarrassment from exposing her breasts and happiness from the praise.
"So, you'll touch your student's pretty breasts a lot today, right…?"
Ryuz looked at me with anticipation, shyly pushing her breasts forward.
Instead of answering, I grasped her breasts with both hands.
"Ah~♥"
The sheer size of her breasts was moving just to touch.
Their unique firmness seemed to push against my palms, yet at the same time, they gently enveloped my fingers as if nurturing them.
No matter how much I touched them, her breasts never ceased to amaze me.
"Ah~♥ Your hands feel so good, Teacher…♥ Your movements are so lewd…♥"
I enjoyed the softness by stroking her all over and gripping them tightly in my hands.
Whatever I did, Ryuz seemed to feel it, trembling each time.
"Ah… Teacher…♥ My breasts are ticklish… Huh~!"
Her nipples, buried within, reacted to the touch, becoming erect and prominent.
The sight of her nipples slowly protruding was astonishingly erotic.
"Have your nipples gotten used to sticking out like this?"
"Aing♥ It's natural to react when Teacher touches them♥ Ah♥"
I teased her fully erect nipples by flicking them with my fingers.
Her waist quivered as I pinched them with my thumb.
"Ha…♥ Te-Teacher, wait a moment…♥ If you do that… Huh~♥"
As I enjoyed her breasts, Ryuz spoke in a pitiful voice.
"Te-Teacher… just a moment…♥"
"Why?"
"Can I serve you today?"
"Serve?"
"Yes, I don't want to be the only one feeling good every day."
Ryuz smiled mischievously, cupping her breasts as if emphasizing them.
"I want to make Teacher feel really good with my cute breasts…♥"
Her breasts were almost explosively large rather than just cute.
Just looking at her pale breasts was pleasurable, so I nodded.
I wondered how Ryuz, who knew nothing about men just a few days ago, would serve.
"Then, excuse me for a moment♥"
As Ryuz pulled down my pants, my erect penis sprang out like a fountain.
She nestled it between her large cleavage.
"Ha…♥ Teacher's penis is so hot…♥ It feels like it's burning my breasts…♥"
Ryuz started rubbing it between her breasts, moving them back and forth.
This was the commonly known paizuri technique.
It seemed she got the hint from the book.
'Paizuri from a young noble lady like her. This is a luxury in its own right.'
And with Ryuz's enormous breasts, it was beyond words.
The soft breasts enveloping from all sides provided a different kind of pleasure than a vagina.
"How is it, Teacher? Do you like my breasts?"
"Yes, they're great. Breasts that can drive any man crazy."
"Hehe…♥ I'll work harder to please you…♥"
Elated by the praise, Ryuz energetically moved her breasts, continually stimulating me.
She rapidly moved them up and down and vigorously rubbed them from side to side.
The tightness of her firm breasts around the tip was incredibly stimulating.
The large size also provided immense visual satisfaction.
"I'll serve you until you're satisfied. Just relax and enjoy, Teacher♥"
While shaking her breasts, Ryuz pursed her lips and lightly kissed the tip.
Then she started to suck it like candy.
A thrilling pleasure surged from my penis up my spine.
'Wow, paizuri and fellatio.'
Ryuz was indeed a fast learner.
As her breasts stimulated from both sides and she sucked the tip, I quickly felt the urge to climax.
I enjoyed Ryuz's service for a while before ejaculating profusely.
Throb! Throb!
"Uhm…! Suck! Huuh!"
Ryuz eagerly swallowed the ejaculated semen.
Still inexperienced in fellatio, she couldn't swallow it all, and some dribbled down.
As the semen flowed down to where her cleavage met, Ryuz gathered her breasts, as if to show it off.
"Thank you for covering my breasts with so much semen, Teacher♥"
Then she leaned over her breasts to consume that as well.
Seeing her drink the semen I ejaculated, despite just climaxing, made my penis throb again.
"Huh, this won't do."
"Te-Teacher? Did I do something wrong?"
I stroked Ryuz's head as she looked up anxiously.
"I need to punish a lewd student right away. Spread your legs now."
"Ah…♥ Yes!"
Ryuz lay down on the bed with a bright, spring-like smile and spread her legs.
Then, with her own hands, she spread her vagina wide open.
"Please punish your lewd student's vagina… Thrust your penis into it, Teacher♥"
I felt satisfaction at her training her techniques according to my tastes.
I pushed my penis into her thoroughly wet vagina.
"Haaaaaaah♥"