Hara Marriage ~Tabegoro Body wa Ninshin Chuu!?~

Kanako, the protagonist's girlfriend, is pregnant! They forgot contraceptives during their first time, and she got knocked up. Unfazed, Kanako wants to keep the baby. The protagonist, unwilling to let her face parenthood alone, decides to take responsibility. But her mother, Kikuna, steps in and forces them to start living together as husband and wife immediately. Their parents had hoped for a more gradual romance, but with Kanako already pregnant, it's too late. The protagonist's burning libido goes unfulfilled, so Kanako agrees to help explore pregnancy-safe eroticism. Surprisingly, Kikuna joins in, offering herself as a substitute! Where will this bizarre situation lead?