Is mammary intercourse allowed

Wa’alaykum as Salām wa rahmatullāhi wa barakātuhu,

Islām has allowed for a man to derive benefit and pleasure from all parts of his wife’s body with the exclusion of the anus; hence, mammary would be permissible.

However, some Jurists have opined that it is prohibited.

We, therefore, advise that caution be exercised in this regard and one that one abstains from such a practice unless there is a genuine need to do so i.e., in the event that one’s wife is menstruating and there are no alternative methods of  fulfilling one’s desires.

(رد المحتار 3/371)

And Allah subhanahu wa ta’ala knows best.