When the sperm comes out, recite the following dua in the heart:
اللَّهُمَّ لَا تَجْعَلْ لِلشَّيْطَانِ فِيمَا رَزَقْتَنِي نَصِيبَاً
"O Allah, let Satan not be part of the children You grant us".
In the Name of Allah, the All-Merciful, the All-Compassionate. Bismi'llahi 'r-Rahmani 'r-Rahim. Praise be to Allah, the All-Powerful, the All-Knowing, the All-Wise, the All-Generous, the Noble, the Compassionate Lord, the One who revealed the Wise Remembrance and the Glorious Qur'an to the Envoy, whom He sent to convey the Right Religion and the Straight Path.