Sayyiduna Abu Sa'id (may Allah be pleased with him) said: I heard the Messenger of Allah (peace and blessings be upon him) say: "Two men should not go out to relieve themselves in such a way that their private parts are uncovered (exposed) while they are talking, for Allah Almighty is intensely angered by that."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الطهارة / 483