It is narrated from Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) forbade that a woman should lie with another woman in a single garment and then describe her to her husband, as though he were looking at her; and he forbade that, when you are three, two should converse privately leaving out the third, because that grieves him, until he mixes with the people.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13563