Just recently learned (via unbidden gossip! I hate gossip!) that decades ago they used to be a lesbian couple, but that their friendship has been non-sexual for decades. Carol depends on Sue very much to manage the household, since she is unable to walk and is losing her mental acuity.
This might be the kind of situation Pope Francis would be thinking of. My impression is that it's not unusual for some older lesbians to ditch sex in middle age but to remain devoted for life. Whether they have repented their younger lesbian sexual vice is between them and their Confessor, their God or their diary.
As for me, it's none of my business. There's surely no sin in their just living together.
Of course people live together for other reasons than having sexual relations and I wouldn’t think anything about people living together. We, at least I, was talking admitted actual homosexuals and the church.