The bathroom door opened carefully, and Chaerin emerged through a veil of pale steam.
Her freshly showered body carried the clean, youthful scent of body wash.
Even though she had dried her hair, a faint dampness still clung to the strands, leaving them slightly wet, while the hot vapor had left her fair cheeks flushed and glowing.
The moment her breasts were about to be touched, every trace of her usual grumbling vanished; only the face of a shy young girl remained.
Chaerin wore a loose short-sleeved pajama top.
Through that thin fabric the rounded contours of her full, rising breasts stood out in clear relief.
“…Were you still looking?”
Spotting me with the textbook still in my hands, she quickly averted her eyes.
I gave a quiet laugh, set the book aside, and beckoned her over.
“Come here.”
Chaerin hesitated, lips working as if she might protest.
Then, resigning herself, she trudged forward and carefully settled into the chair in front of me.
Even after a long shift and cooking dinner she should have been exhausted, yet her eyes trembled with the faintest spark of anticipation.
“Can I touch your breasts?”
Her shoulders gave a little shiver.
Head bowed low, she murmured in a tiny voice,
“…D-Do whatever you want.”
“I’ll follow the textbook exactly.
Think of it as preparation.”
I spoke lightly as my fingers found the hem of her pajama top.
Thin, soft cloth under my touch.
When I slowly lifted the fabric, her pale, slender waist and flat belly came into view.
Chaerin sucked in a sharp breath and tensed her stomach; her whole body had gone rigid with tension.
Once the top was completely removed, a pale-pink bra appeared.
It was the first time I had ever looked at my twin sister’s undergarment like this.
The unfamiliar sight made my cock grow thick and heavy in an instant.
The bra could not fully contain her generous breasts; the soft upper swell spilled over the cups just a little.
“Take this off too.”
“….”
Instead of answering she kept her head down and, with trembling fingers, reached behind her back for the clasp.
Whether from anticipation or nerves, her fingers fumbled several times before a soft click sounded and the bra came free.
At last the two ripe breasts hung fully exposed before my eyes, nothing left to hide them.
“Whoa…”
An involuntary gasp of admiration left my lips.
Two full breasts sat beautifully against her fair skin.
At their tips rested shy, light-pink areolas and small nipples that still slept, soft and dormant.
I recalled the textbook passage.
“Get ready.”
“…What?”
“The book said so, didn’t it?
Make your nipples stand up before you welcome your master.”
Her face flared scarlet.
“A-Are you insane?
H-How am I supposed to do that…!”
“You have to do it yourself.
Hurry.”
I folded my arms and urged her on like a strict instructor.
Ordinarily I could never be this firm with Chaerin, yet somehow tonight was different.
Perhaps I possessed a natural talent for handling women.
In my previous life I had never even properly held a girl’s hand, so I had never known such a gift existed inside me.
After a brief hesitation Chaerin brought her trembling hands to her own chest.
Her small fingers lightly gathered the fabric of her pajama top and began to rub her nipples gently through the cloth.
Watching her caress her own breasts, eyes squeezed shut in embarrassment, made me clench my fists with pure excitement.
Before long a thin moan slipped from her lips.
“Hnn…”
A moment later she carefully withdrew her hands.
I held my breath and watched the change.
Nipples that had been nearly flat only moments ago now stood stiff and proud.
Those tiny hard peaks, fully erect and demanding attention, were the perfect signal that she was ready.
“Good girl.”
With a satisfied smile I finished stripping away her pajamas and finally stretched my hands toward her breasts.
The instant my fingertips met her warm, soft flesh, her whole body jerked hard.
“Hyaah!”
A violent, electric reaction ran through her.
For a second I wondered if I had done something wrong, but the expectant light in her eyes told me to continue.
I cupped her right breast completely with my palm.
Soft, overflowing flesh filled my hand, pliant and full beyond what one palm could hold.
I applied slow pressure, rolling my hand in gentle circles.
Under my palm I felt the hard little nipple, and every time I pressed it Chaerin’s body twitched.
“Haah… nnngh…!”
She twisted her hips and bit her lip, fighting the pleasure.
By every standard I had known, a woman should not collapse so easily from mere breast play.