What are the limits of eating and drinking in relatives' homes? Is permission required to consume what they offer? If my aunt offers food and my husband disapproves, is it forbidden for me?

The basic principle is the prohibition of benefiting from another's property except with their willing consent, based on the Prophet's (PBUH) saying: "The property of a Muslim is not lawful except with his willing consent." However, Allah has permitted eating from the homes of relatives, such as fathers, mothers, brothers, sisters, paternal uncles, paternal aunts, maternal uncles, and maternal aunts, without explicit permission, due to the prevailing custom of leniency. This is unless the homeowner is stingy and unwilling, in which case it is forbidden to eat from their food without their permission.

If the maternal aunt offers food, and you know that her husband is not pleased with that, then if it is from her own property, there is no harm in taking it. But if it is from her husband's property, it is not permissible to take it, because his consent has not been obtained.