Asalamualaikum
If three men all pray salah together where do the two followers stand? Behind or to the side of the imam?
If the congregation consists of three or more males then the followers will stand behind the Imam.
قام رسول الله صلى الله عليه وسلم ليصلي فجئت حتى قمت عن يساره فأخذ بيدي فأدارني حتى أقامني عن يمينه ثم جاء جبار بن صخر فقام عن يسار رسول الله صلى الله عليه وسلم فأخذ بيدينا جميعا فدفعنا حتى أقمنا خلفه
Allah's Messenger ﷺ stood up to pray and I came and stood at his left side, so he took my hand, turned me round, and set me at his right side. Then Jabbar b. Sakhr came and stood at the left of Allah's Messenger ﷺ, so he took us both by the hand, pushed us back, and made us stand behind him.