Answer
Wa `alaykum As-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- It is absolutely sinful to establish sexual intimacy or derive sexual satisfaction from anyone other than one’s own lawfully married spouse.
2- If you mean to ask whether married couples are allowed to derive pleasure by oral sex, then the answer is, yes, provided they are doing so consensually.
In his response to your question, Sheikh Ahmad Kutty, a senior lecturer and Islamic scholar at the Islamic Institute of Toronto, Ontario, Canada, states:
Islam is a religion of chastity and morality. It aims at building a solid society on bases of purity, modesty, morals, and good manners. Therefore, Islam blocks all paths that lead to evil. Muslim jurists adopt a juristic principle : What is conducive to haram (unlawful) is itself haram.
Islam has taken a firm and decisive stance against zina (fornication or adultery). Allah the Almighty commands in explicit and unequivocal words: “And come not near unto adultery. Lo! it is an abomination and an evil way.” (Al-Israa’ 17:32)
Thus, Islam not only prohibits zina, but also closes all the avenues and means leading to it. This is achieved by prohibiting everything that leads to stimulating desires, opening ways for illicit sexual relations between men and women, and promoting indecency and obscenity.
If the purport of your question is to inquire whether it is considered zina to engage in oral sex with anyone other than one’s married partner, the answer is most categorically and definitely, yes. In other words, it is nothing but zina, pure and simple. For according to the explicit teachings of Islam, it is absolutely sinful to establish sexual intimacy or derive sexual satisfaction from anyone other than one’s own lawfully married spouse.
If, on the other hand, you mean to ask whether married couples are allowed to derive pleasure in this way from each other, then the answer is, yes, provided they are doing so consensually.
To derive sexual satisfaction from anyone other than one’s marriage partner in any way is considered zina in Islam. This is according to the explicit commandment of Allah: “And come not near unto adultery. Lo! it is an abomination and an evil way.” (Al-Israa’ 17:2)
The Prophet (peace and blessings be upon him) further said, “Guard your private parts [that is, keep yourself chaste and pure by abstaining from any sexual relations with anyone] except from your lawful spouses.”
Allah Almighty knows best.
Excerpted, with slight modifications, from: www.islam.ca