بسم اللہ الرحمن الرحیم

الجواب وباللہ التوفیق

Oral sex is one of the most disgusting, immoral, and obscene acts that should be avoided. 

Umm Al-Mumineen Hazrat Ayesha (may Allah be pleased with her) said:” I have never seen the private parts of the Prophet (peace and blessings of Allaah be upon him).

مارأیت فرج رسول اللہ صلی اللہ علیہ وسلم قط۔ [سنن ابن ماجہ :138،ابواب النکاح

When one of you goes to his wife, he should cover himself, and not become naked like a donkey.

اذا اتي احدكم اھله فليستتر ولا يتجرد تجرد العيرين (سنن ابن ماجہ:ابواب النکاح

This shows the importance of modesty in Islam! How can it be permissible to lick each other's private parts and take them in one's mouth when it is disliked to be completely naked while being close to one's wife

In this context, Mufti Abdul Rahim Lajpuri (RA) writes in response to a question:

Though the visible private parts are pure/ clean, but it is not required that every clean thing should be taken into the mouth and licked. The moisture in the nose is pure. Who would in his right senses insert his tongue into the nose and suck its secretions into the mouth? No, none at all!

In the same logic, it is not permissible to kiss a woman's private parts andor lick them. It is disgusting and strictly sinful ...... Just Think! Recitation of the Holy Qur'an, Darood Sharif, and "adhkar" are all spoken through this mouth. Water and food also goes through the same mouth.

How then the same mouth and tounge be used for such impure, unnatural, unhealthy and perverted sexual pleasure. 

(فتاویٰ رحیمیہ،۱۰/۱۷۸)

فی النوازل اذا ادخل الرجل ذکرہ فی فم امرانہ قد قیل یکرہ وقد قیل بخلافہ (کذا فی الذخیرۃ عالمگیری :۵ / ۳۷۲)(احسن الفتاویٰ میں ہے اقول المبیح مجھول منکر وقولہ مردود شرعا وعقلا احسن الفتاویٰ  : ۸ / ۴۵)

(فتاویٰ دارالعلوم دیوبند)

 فقط واللہ اعلم بالصواب