What if they publicly say they live together but don’t have sex? What if they privately tell a priest this and no one else? I ask because I don’t know.
FReegards
A couple who are living as “brother and sister” may receive Communion anyplace where they can do so without scandal. Such a place would be where they are unknown, or, where they are known to be living chastely. In a small parish in a small town, that wouldn’t be uncommon.