All perfect praise be to Allah the Lord of The Worlds. May His blessings and peace be upon our Prophet Mohammad and upon all his family and companions.
When sexual intercourse takes place and sperm is ejaculated outside the vagina, this is called `Azl or coitus interruptus. According to the opinion of the majority of scholars, this practice is permissible by mutual consent of both spouses particularly when there is medical grounds for that. The evidence on this is that Jabir narrated : "We used to practice coitus interrupt us while the Qur'an was being revealed. Jabir added: We used to practice coitus interrupt us during the lifetime of Allah's Messenger (PBUH) while the Qur'an was being Revealed." {Related by Bukhari and Muslim}. And Allah The Almighty Knows Best.