My question is somehow embarrassing. Is it permissible for a wife to pierce different parts of her body, such as the underlap, navel, and tongue in order to attach earrings with her husband's permission? Please advise. Thanks for your efforts. May Allah help you work for the interest of the Ummah (Muslim community).

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

It is permissible for a woman to adorn herself for her husband with whatever is permissible in the Sharee'ah. Piercing the ear in order to put an earring is a controversial issue. The preponderant opinion, however, is that it is permissible, because it was authentically reported that women used to do it during the lifetime of the Prophet, sallallaahu ‘alayhi wa sallam.

Shaykh Salih Al-Fawzan said:

There is nothing wrong with piercing a little girl's ear in order to adorn it with jewelry. Many people still do this, and even at the time of the Prophet, sallallaahu ‘alayhi wa sallam, women used to wear jewelry in their ears and elsewhere without having their action disapproved. As for the pain that the girl experiences, this is done for her interest, because she needs to wear jewelry and adorn herself. Piercing the ears serves a permissible purpose and is allowed because of a need. Just as it is permissible to carry out surgery and cauterize a girl if that is needed on medical grounds, it is also permissible to pierce her ear in order to wear jewelry in it, because it is something that she needs, and it is something that does not hurt very much nor has a great effect on her. [Fataawa Ash-Shaykh Al-Fawzan]

Shaykh Muhammad As-Salih Al-‘Uthaymeen was asked about piercing a girls’ nose or ear for the sake of beautification. He replied:

The correct view is that there is nothing wrong with piercing the ear, because it is a means to wear permissible jewelry. It was authentically reported that the women during the era of the Prophet, sallallaahu ‘alayhi wa sallam, had earrings which they wore in their ears. The pain is simple, and if the piercing is done when the girl is young, it heals quickly. As regards piercing the nose, there are no statements of the scholars about it, but it is a form of deformation of the creation in our view. Perhaps other scholars do not hold this opinion. So if a woman is in a country where piercing the nose is a familiar form of beautification, then it is permissible for her to pierce her nose in order to put jewelry in it. [Majmoo’ Fataawa Ibn ‘Uthaymeen]

Shaykh ‘Abdul-Muhsin Al-‘Abbad was asked about piercing a woman's nose for the sake of beautification. He answered, "If it is the women's habit to beautify themselves in this way, then it is permissible and it is the same as piercing the ear. This habit used to be practiced until recent times, but it is no longer practiced in present times." [Sharh Sunan Abu Daawood]

Thus, it is permissible to pierce the ear and nose for beautification. As for piercing the navel, tongue and similar parts of the body, the scholars did not give statements in this regard. The soundest opinion, however, is that it is disallowed due to two reasons: firstly, mutilation and pain are more severe in such spots of the body; secondly, women mostly do not need beautification in such spots. Rather, piercing such parts features deformation rather than beautification. The fact that the husband accepts this action does not make it permissible in the Sharee'ah. Moreover, it may be a habit of some immoral women who live in morally degraded societies. 

Allah knows best.