My Girlfriend Was Fucked By My Neighbor. "Complaints From Dull, Middle Aged People Edition"

隣人に俺の彼女が寝取られて。 「冴えない中年からのクレーム編」 辻井ほのか

We had been dating on the premise of marriage since college, and recently moved to a new house, but our neighbor, Saeyama, who is noisy, complains every time something happens. Honoka and the others have lived with consideration for each other, but Saeyama has reached the limit of his patience and attacks him to cover up her mouth.