All acts that aim at satisfying and pleasing the spouses are allowable so long as two things are avoided, that is anal sex and having sex with a wife while she is still in her menstruation. Thus, it is permissible for a husband and a wife to practice cunnilingus and fellatio. Following we’d cite the opinions of some well-known Muslim scholars in this regard:
The eminent Muslim scholar, Sheikh Yusuf Al-Qaradawi states: “I was asked about oral sex in America and Europe when I began to travel to these countries in the early 70s. We are not used to be asked these questions in our Muslim countries. Those Western people are accustomed to stripping naked during sexual intercourse. These are communities of nakedness, and from the licentiousness of the woman that she wears nothing to screen her body in her daily life.
So, they are in need of more excitements during copulation. However, men in our Muslim societies see nothing in the Muslim woman that can excite them on the basis of her wearing either Hijab (veil) or Niqab (face cover). But concerning whether being in complete nakedness during practicing copulation is lawful or not, the Prophet of Allah, peace and blessings be upon him, is reported to have said, “Guard your private parts except from your wife or your slaves.”
Muslim jurists are of the opinion that it is lawful for the husband to perform cunnilingus on his wife, or a wife to perform the similar act for her husband (fellatio) and there is no wrong in doing so. But if sucking leads to releasing semen, then it is Makruh (blameworthy), but there is no decisive evidence (to forbid it).
these parts are not dirty like anus, but it is ordinarily disgusting to man. But there is no decisive evidence to make it unlawful, especially if the wife agrees with it or achieves orgasm by practicing it. Allah, Exalted and Glorified be He, says: “And who guard their modesty, save from their wives or the slaves, that I heir right hands possess, for then they are not blameworthy, but Who so craveth beyond that, such are transgressors.” (Al-Mu’minun: 5-7)”
In the light of this, scholars maintain that the husband is allowed to enjoy his wife through any means of enjoyment except anal sex, for that is strictly forbidden.
Dr. Ali Jum`ah, professor of the Principles of Islamic Jurisprudence at Al-Azhar Univ., says further that licking, sucking and kissing spouse’s sexual organs are all allowed, as long as it gives a person sexual gratification that will keep him away from Haram (unlawful) or starring at opposite sex (marriageable). But every Muslim must keep in mind that sexual intercourse is just a lust and passion that must be satisfied in a lawful way; it’s not to be perceived as necessary as foods and drinks, as it’s the case in the Western perverted ideology.
Shedding more light on this, Dr. Sabri `Abdul Ra’ouf, professor of Islamic Comparative Jurisprudence, at Al-Azhar Univ, says that it’s allowed for the married couple to enjoy each other as long as what they do does not run counter to the teachings of Islam or violate the public norms. He also gives support to the view of Sheikh Al-Qaradawi that oral sex or kissing private parts of the spouse is something viewed disgusting to Muslims, but if the aim is just kissing (without having constant indulgence in it) it’s not sinful to do that, but people of high morality normally keep away from that, as not to give in to imitating non-Muslims.”
In conclusion, it has become clear now that oral sex is not prohibited, but it is not the normal choice for committed Muslims and Muslimahs. That’s, despite that oral sex is not Haram, it is completely disgusting and does not conform to the pure taste and decency of a Muslim personality.

Here, it should be noted that one of the main objectives of Shari`ah is to safeguard the life of people and keep them healthy. Based on this, if it is scientifically proven that oral sex or such practices cause mouth cancer or form a danger on the health of a person who practices it, then it becomes totally prohibited.