I saw Ibn Umar speaking privately with a man when another man came between them. He struck his chest and said, "The Messenger of Allah ﷺ said, 'When two people are conversing privately, a third must not come between them without their permission.'"
حدثنا نوح أخبرنا عبد الله
رأيت ابن عمر يناجي رجلا فدخل رجل بينهما فضرب صدره وقال قال رسول الله ﷺ إذا تناجى اثنان فلا يدخل بينهما الثالث إلا بإذنهما