Kikon Status dake Itadakimasu!

27-year-old Riko has been dating her partner Kurumi for 3 years now and neither of them plan to come out about their sexuality. However, they've finally become unable to stand the pressure from the constant questioning by their family and surroundings about when they're getting married. That's when they decided to get their "married" status by "marrying" a gay couple and entering into their family register. Now, the four of them are living together!

(Source: Kadokawa, translated)