´It was narrated from Abdullah that the Messenger of Allah(ﷺ) said:` "When you are three, two should not converse (privately) to the exclusion of their companion, because that makes him sad."
Hadith ReferenceSunan Ibn Majah / Chapters on Etiquette / Hadith: 3775
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:صحيح مسلم