Is it obligatory to maintain kinship ties with relatives who consume and trade in intoxicants, and is it permissible to eat their food?

The Wise Lawgiver (Allah) commanded the upholding of kinship ties. If relatives are disobedient and openly commit sins, this does not prevent maintaining ties with them. Rather, it may become a duty to advise them. The proof for the permissibility of maintaining ties with a disobedient relative is that the Messenger of Allah (peace and blessings be upon him) commanded Asma bint Abi Bakr to uphold ties with her polytheist mother.

As for their food, it is not permissible to eat from it unless they have another source of income besides trading in forbidden things. This kinship tie must be limited to what is obligatory, without being overly familiar with them or extensively accepting their invitations. It is obligatory to declare dislike for their actions and not to sit with them while they are engaging in forbidden acts. Boycotting them is permissible if it is beneficial and does not lead to a greater harm, and it is not considered severing ties with this intention.