'Abdullah reported that the Prophet, may Allah bless him and grant him peace, said, "When there are three people, two should not converse together to the exclusion of the third for that would grieve him."  

قَالَ النَّبِيُّ ﷺ إِذَا كُنْتُمْ ثَلاَثَةً فَلاَ يَتَنَاجَى اثْنَانِ دُونَ الثَّالِثِ فَإِنَّهُ يُحْزِنُهُ ذَلِكَ  

Ibn 'Umar reported something similar from the Prophet, may Allah bless him and grant him peace. He stated, "We said, 'If there are four?' He said, 'Then it will not harm him.'"  

عَنِ النَّبِيِّ ﷺ مِثْلَهُ قُلْنَا فَإِنْ كَانُوا أَرْبَعَةً؟ قَالَ لا يَضُرُّهُ  

'Abdullah reported that the Prophet, may Allah bless him and grant him peace, said, "Two should not converse to the exclusion of another until they are mixing with people since that would distress him."  

عَنِ النَّبِيِّ ﷺ قَالَ لاَ يَتَنَاجَى اثْنَانِ دُونَ الْآخَرِ حَتَّى يَخْتَلِطُوا بِالنَّاسِ مِنْ أَجْلِ أَنَّ ذَلِكَ يُحْزِنُهُ  

Ibn 'Umar said, "When there are four, there is no harm."  

عَنِ ابْنِ عُمَرَ قَالَ إِذَا كَانُوا أَرْبَعَةً فَلا بَأْسَ