これって、リア充？～黒ギャルが、ドーテーを教育するそうですよ～（Kore tte, Riajuu? ~Kuro Gyaru ga, Doutei o Kyouiku Suru Sou Desu yo~）

"Hey, what the hell are you staring at? Who the hell are you again? Uh…"
"Don’t know this guy! Hey, you! What are you gawking at? Get outta here!"

In the classroom, there was a pair of sisters—completely naked. Even if no one was around, stripping down to nothing in an unlocked classroom—what were they thinking? Then they called me a "creepy pervert" and made me their servant, swearing me to secrecy. Well, it wasn’t so bad—just running errands for them in exchange for some money. I didn’t really mind.

That’s how things went for a while, until one afternoon after school.
The free-spirited sisters were sitting in chairs with their legs spread, holding what seemed like a debriefing session about their sexual escapades with various guys.
Just listening to their stories made my imagination run wild with all sorts of dirty thoughts.
Before I knew it, I was hard.

"What’s with the squirming? Huh?"
"Oh, are you… are you hard!? Did you get turned on listening to us? Seriously!?"
"Well, it’s kinda obvious. You probably don’t have anyone to show it off to, right? We’ll take a look for you. Happy now?"

Realizing there was no point in resisting or arguing, I just…

[Translated from getchu]