Responses
I don’t know if you have read it yet but this is the only one I could think of:
http://www.mangago.zone/read-manga/kazoku_ni_narouyo/
They have a sequel to it too, about when the couple were young, if you want to read it afterwards:
http://www.mangago.zone/read-manga/itsuka_koi_ni_naru_made/
Any Yaoi Manga, about couple who have already been together and are living with each other? Or about how they became a couple and then moved in together, sweet thing pleasee