Before sexual intercourse with the wife

Bismillāh. Allāhumma jannibnash-Shayṭān, wa jannibish-Shayṭāna mā razaqtanā. With the Name of Allah. O Allah, keep the Devil away from us, and keep the Devil away from that which You provide for us. Reference: Al-Bukhari 6/141, Muslim 2/1028.