What is the ruling on a man unveiling himself before his brothers' wives, claiming they were raised with him, and is it permissible for a woman to unveil herself before her husband's brothers?

A man uncovering himself before his brothers' wives, entering upon them, and mixing with them while they are unveiled or not wearing a niqab, is a reprehensible act, due to the hadith: "Beware of entering upon women," and Allah's Almighty saying: "Tell the believing men to reduce [some] of their vision and guard their private parts." It is most likely that this mixing leads to the formation of illicit relationships, and it involves betrayal of spouses, severing ties of kinship, and injustice to the wife. Equating non-mahram women with mahram relatives is a false analogy. A husband inviting his wife to unveil before his brothers is a sin and an abomination, and is considered dayouth (pimping), due to the hadith: "Three types of people Allah has forbidden Paradise for: an alcoholic, a disobedient child, and a dayouth." This husband must adhere to Allah's limits, avoid mixing with his brothers' wives, and not invite his wife to unveil before his brothers.