A bona fide question: doesn't the "brother and sister" option in the interpretation to Familiaris Consortio, blow the access to the Eucharist restrictions wide open?  Suppose you are "living like brother and sister."  But then you fall off the wagon one week.  Are you toast?  Never to receive Communion again, or is this a sin that can be absolved after proper sacramental confession, purpose to amend, number and kind, etc.  So you get back on the wagon, and you are on your merry way, n'est–ce pas?  You could be eligible to receive the Eucharist so long as you were on the wagon, though you might intermittently be falling off the wagon, correct?  So how is Amoris Laetitia such an aberrant deviation from the practice allowed under Familiaris Consortio?  Doesn't Familiaris already effectively provide for Communion for couples who are, in fact, not living like brother and sister, so long as they are trying to do so?  Isn't this pastoral leeway?