Oral Sex in Islam: Is it Permissible
Sheikh Muḥammad Al-’Ānsi ḥafidhahullāh
“This question…الله المستعان…(Sheikh takes a deep breath and sighs)…seeing as the question has been put forth…This (oral sex) is not something legislated. It is not permissible. His wife’s mouth is not a place for sexual intercourse. الله المستعان. A person should not go against the innate disposition (Al-Fiṭrah), sound reasoning and the human nature. I mean, if a human, or even an animal, desires a female, what does he say to himself? Where does he go?…You find the animal, if he finds a female, he goes and searches for her vagina. This is the case in the animal world, in the bird world, and other worlds that Allāh created. He goes and searches for her private parts. Even the donkey searches for the female’s private parts. He overcomes her and pursues her as you find with dogs. So how is it that the human being who Allāh Almighty has honoured resorts to such despicable and vile acts?! Yes, how does he allow himself to place something which some of the scholars deemed impure (i.e. Semen); yes it is an issue of differing, some said it is pure and others said it is impure. So even if it is pure, it is still filthy; because it comes out of the urine outlet and carries an unpleasant odor. Also, the Prophet ﷺ used to wash off semen if it got on his garment – while it was still moist, and even when it dried, Aishah (the mother of the believers) would scratch it off his garment. Thus, it is dirty in itself, so how is it appropriate for a man to place it in his wife’s mouth?! And how can the wife accept this?! Moreover, the mouth is not a place for desire (i.e. sexual intercourse), nor will he find sexual gratification in that. I consider this to be an act of violence والله المستعان. I ask Allāh to protect us and our brothers from these vile acts, and perhaps the one who does this will go on to have intercourse with her, perhaps anally, or have intercourse with her in other places. Yes, a man may enjoy himself with his wife, as Allāh said:
{ نِسَاۤؤُكُمۡ حَرۡثࣱ لَّكُمۡ فَأۡتُوا۟ حَرۡثَكُمۡ أَنَّىٰ شِئۡتُمۡ}
“Your wives are a place of cultivation [i.e., sowing of seed] for you, so approach your place of cultivation as you wish.” [Sūrah Al-Baqarah: 223]
Similarly, the Prophet ﷺ said:
((اصنعوا كل شيء إلا النكاح))
“Do everything except intercourse.”
Based on this the scholars stated that it’s okay for a man to enjoy his wife by means of fondling…gratifying himself with her thighs, backside, etc. as long as he avoids the anus and menstruation…Aside from that it permitted for him according to Sharia law to enjoy himself with his wife, but it is important to avoid the places of impurity (anus and menstruation). It is permissible [to fondle her] even if it leads to ejaculation. But other than this, like the mouth, then this is despicable. Despicable! Yes, and it is feared that this is something that has been taken from what is circulated from the Kuffar; for they are people of impurity and filth. That which is spread of pornography, which we haven’t witnessed ourselves الحمد لله; where this one has intercourse with a woman in her mouth, and this one has intercourse with her in her ear, and this one has intercourse with her in her anus, we seek refuge with Allah, and this one in her private parts; like dogs, rather they are worse than dogs. In fact, if the dogs were to gather together, they would never do this. Perhaps they will fight one another competing for the vagina.”
Follow up question: If a man ejaculates after oral intercourse, do he and his wife both have to make Ghusl?
Sheikh: “He has to make Ghusl if he ejaculates, but there’s nothing upon the wife other than to fear Allāh and avoid this despicable act.”
TN: Pre-cum is impure and there’s a very high chance that it may enter the mouth unnoticed 
The scholars have mentioned that swallowing impurity is not permissible 