Abu Sa'id al-Khudri reported Allah's Messenger ﷺ as saying, “The most serious breach of trust in Allah’s sight on the day of resurrection ...” A version has, “Among those who will have the worst position in Allah’s sight on the day of resurrection is the man who has intercourse with his wife, and she with him, and then spreads her secret.”* * i.e. talks about the subject to others, or tells people about defects or beauties he has found in her. Muslim transmitted it.