DOCP-139 — Does My Serious Little Sister Masturbate Too?! She's Going Crazy Like That!? I'm Going To Fuck My Little Sister's Pussy In Her School Uniform And Cum Like Crazy, No Questions Asked!

My little sister is a hard-working and serious student, but she ignores me when I tease her... When I peek into her room, she's masturbating. ...No, no, what, just kidding, she's cumming that much!? I couldn't stop being curious and as I watched, I got so excited that I immediately plunged into her from behind without asking any questions! I came inside her, but it turned her on!??