MSTG-007 - Brother's Wife. I realized my wife was being fucked by my brother right in front of me, Kurumi Tamaki

The older brother, living with his younger brother's couple, grows annoyed by their life. He starts spying on his sister-in-law, Kurumi, and discovers her secret chats. Realizing she's unsatisfied, he hides his identity, lures her out, and takes her. He knows exactly what she wants, and after a session, she happily agrees to do it again.