性活指導員 ～キモ男が不妊に悩むピュアな若妻に手取り足取りアクメレッスン！ラブラブ寝取り種付けで理想の嫁に!～

The protagonist was an unattractive guy working at the planned parenthood clinic.
Wives came for fertility counseling and he would help them out as an "educator".
One day Madoka walked through his doors looking for advice.
Under the guise of official business and a plan to turn her into his own devoted bride, he began the orgasmic lesson!

[From DLsite English]