Netorareta Bakunyuu Seisou Tsuma Hitomi: Oikko ni Torotoro ni Tokasaremashita

Hitomi lived a stale life with her unattentive husband until her nephew-in-law moved into their home. When she winds up in a sexual relationship with him, she discovers what real, passionate sex feels like!
(Source: Irodori Comics)
Note: A live-action AV adaptation (START-173) was released on September 9th, 2024.