YMDD-181 — Little Sister Ntr Incest: I Peeked At My Overly Sensitive Busty Sister's Sex And Ended Up Having B**-Related Sex... Tsukimiya Nene

My classmate's friend is cool, good at studying and sports, and popular with the girls. I'm jealous, but he has a girlfriend. I heard that she's a sweet girl and has a very sensitive body. But one day, I saw my friend getting cozy with my sister! Is his girlfriend really my sister?! Since then, I couldn't stop thinking about my sister's body...and before I knew it...I was rushing into the bathroom where my sister was.