Honestly, I might eat my hat here and go on a rabbit hole about early priestly marriage myself.

“This great synod absolutely forbids a bishop, presbyter, deacon or any of the clergy to keep a woman who has been brought in to live with him, with the exception of course of his mother or sister or aunt, or of any person who is above suspicion.” Okay, so as you know, from your source; phrased as so.

en.wikipedia.org/wiki/First_Council_of_Nicaea The wikipedia provides some clarification on the issue. “prohibition of a man and a woman who have both taken vows of chastity to live together in a chaste and non-legalized partnership (the so-called virgines subintroductae, who practiced syneisaktism)” the last word being a Greek term for “spiritual marriage” which was chaste, but also unofficial in the eyes of the law? I’m not sure I’m reading it correctly myself.

en.wikipedia.org/wiki/Syneisaktism