Questions of Sexual Intimacy: Mutual Masturbation & Impermissibility of Wife's Milk

In the name of Allah, the inspirer of truth. All praise is to Allah, Most Merciful and Compassionate, and all blessings and peace to our Master Muhammad, his family, companions, and those who follow them.

A1:Ibn ‘Abidin clearly states the permissibility of mutual masturbation between the husband and the wife, quoting the Mi’raj al-Diraya as saying ‘And it is permitted to masturbate with the hand of one’s wife’. 

Ibn ‘Abidin further explains the difference between this and masturbating with one’s own hand, which is clearly forbidden except in exceptional circumstances, as being that in the former one is satisfying oneself with that which is permissible to gain satisfaction from, namely a part of one’s spouse all of whom one is permitted to seek sexual satisfaction from, whereas in the later one is not.

He adds that therefore just as masturbating with one’s hand is forbidden so is masturbating with one’s own thigh or a wall or any other object.

Based on this reasoning and the explicit text mentioned above concerning the permissibility of a man masturbating with his wife’s hand it can be concluded that the reverse is also permissible, namely the wife’s masturbating with the husband’s hand. [Radd al-Muhtar, 2:400, 4:28, al-‘Ilmiyya]

As for Question 2:
A2: The husband is not permitted to drink his wife’s milk because, in the words of imam al-Haskafi in al-Durr al-Mukhtar, quoting Sharh al-Wahbaniyya,

‘It is a part of a human being and to make use of it without a real need to do so is Haram’. [Radd al-Muhtar, 3:212, Dar al-Kutub al-‘Ilmiyya].

This a general rule in the sacred law:  No part of a human being may be sold or used for nourishment or other ‘deriving of benefit’ (intifa’), beyond that which the Sacred Law has permitted.  The baby’s drinking the mother’s milk is an exception, based on textual permission, due to the ‘real need’ (durura) to do so.

And Allah knows best.