There are two aspects to your query:

1) Possibility of human-Jinn inter-marriages;

2) Permissibility of human-Jinn inter-marriages.

I. Possibility

Many classical scholars are of the opinion that, despite being extremely rare, it is possible for marriage to take place between humans and Jinn (plural: Jann).

Qadhi Badr al-Din al-Shibli al-Hanafi in his masterpiece work on the subject of Jinns, Aakam al-Marjan fi Ghara’ib al-Akhbar wa Ahkam al-Jann, quotes many early Muslims, such as Tha’alabi, Uthman ibn Sa’id al-Dari, A’mash and Abu Yusuf Saruji, who held the view that not only is human-Jinn inter-marriage possible, but rather, there are instances where such marriages have occurred. (Aakam al-Marjan P: 98-104)

Imam Suyuti also mentions a few reports from the early generations pointing to the occurrence of marriage between humans and Jinns. This was supported by Imam Ibn Taymiya who said that humans and Jinns have got married and have had children as a result of their marriage. (See: Laqat al-Marjan fi Ahkam al-Jann by Suyuti)

The classical Hanafi jurist, Imam Ibn Abidin (may Allah have mercy on him) also concurs with this view. He states:

“…This concept [of human-Jinn inter-marriage] is a possibility, because their (Jinn) taking various forms [including the human form] is proven by many Hadiths and incidents. This is why it is reported from the Messenger of Allah (Allah bless him & give him peace) that he forbade the killing of certain snakes [since it may be a Jinn in the form of a snake]…” (Radd al-Muhtar ala al-Durr al-Mukhtar 3/5)

II. Permissibility

As far as permissibility is concerned, most classical scholars are of the view that such a marriage is not permitted. The author of Aakam al-Marjan relates this opinion from Imam Zuhri, Hakam, Qatada, Hasan al-Basri, Hajjaj ibn Artat, Abu Hammad and Imam Ghazali (May Allah be pleased with them).

Imam Ibn Abidin of the Hanafi School explains in his Radd al-Muhtar ala al-Durr al-Mukhtar that the prohibition of human-Jinn inter-marriage (munakaha) is derived from the Qur’anic verse: “And Allah has made for you spouses from among yourselves.” (Surah al-Nahl, V 72) and: “Marry women of your choice…” (Surah al-Nisa, V 3)

He explains that in light of these two verses, spouses can only be from one’s own kind, since Allah Most High used the term: “from among yourselves”. Likewise, “Marry women” refers to females from the daughters of Sayyiduna Adam (peace be upon him), and as such, this permissibility will not be generalized to other species without a clear textual evidence. Moreover, he explains, Jinns can take different forms; hence it is possible for a male Jinn to appear in the form of a female, and visa versa. He adds from Imam Ibn Nujaym’s Al-Ashbah that marriage between a human male and a female Jinni and between a human female and a male Jinn is not lawful due to them being separate species (ikhtilaf al-jins). It was reported that Al-Hassan al-Basri (may Allah be pleased with him) was of the opinion that such a marriage is lawful so long as there are witnesses to it. However, it was later reported that he did not consider it to be lawful. (See: Radd al-Muhtar 3/5)

From the Shafi’i School, Imam Khatib al-Shirbini (may Allah have mercy on him) states in his Mughni al-Muhtaj:

“Prohibited (i.e. invalid) marriages are of two types: 1) Eternal, and 2) temporary. Of the eternally prohibited marriages is that which takes place between different species. As such, it is not permitted for a male member of the human kind to marry a female Jinni [and vice versa]… Allah Most High says: “He (Allah) is the One who has created you from a single soul, and out of him created his wife, so that he may find comfort in her.” (Surah al-A’raf V 189) and: “O people, fear your Lord who created you from a single soul, and from it created its match, and spread many men and women from the two.” (Surah al-Nisa, V 1) (See: Mughni al-Muhtaj, 3/232)

In conclusion, human-Jinn inter-marriages are possible, but extremely rare. However, they are not permitted according to most early Muslims and classical scholars due to human and Jinns being different species and having different origins – something that would result in the marriage being void of the companionship, comfort, love and mercy mentioned by the Qur’an, and as such, the wisdom behind marriage would be lost.

And Allah knows best