Two of you must not converse privately ignoring the third
Ibn Mas'ud, May Allah be pleased with him, said: The Messenger of Allah, may the peace and blessings of Allah be upon him, said, "When three of you are together, two of you must not converse privately ignoring the third till the number increases, lest the third should be grieved."
This Hadeeth entails one of the etiquettes of companionship whether in the way and other than it.
It has its social dimensions. It is a part of good companionship that the Muslims meet for good purposes, deal with each other on the best way, and that each one of them should care for the feelings of the others; so that one may not embarrass the others neither by acts or deeds. Rather, one should do his best to choose the pleasant words and to avoid what angers and harms the others. As stated in the Hadeeth: "The Muslim is the brother of the Muslim." It was previously presented in this book
This noble moral is known to those of sound senses and determination, for they are capable to distinguish between what is harmful and what is useful, and what is acceptable and what is unacceptable.
We will not find an integrated system of public and private relations like the system that Islam has legislated if we have properly understood it, and recognized its aims and dimensions.
The saying of Prophet, may the peace and blessings of Allah be upon him, said: " When three of you are together, two of you must not converse privately ignoring the third." Meaning: A man may not speak with another one in a faint voice.
The prohibition entails that it is disliked if the confidential talk is not so long and was not intended to exclude the third one, as well the third one do not expect something that makes him afraid or angry. However if, these conditions are not fulfilled, such an argument is prohibited due to the relevant harm