The ruling on a woman sitting with her cousin without a hijab on the grounds that she grew up with him

Question:
May Allah reward you. The questioner asks: What is the ruling on a young woman sitting with her cousin, who is an adult, in the same house, without wearing a hijab, on the grounds that she grew up with him since childhood?

Answer:
This is not permissible. The hijab is obligatory for a woman once she reaches puberty; she must wear it even if she grew up with a man. This is not an excuse for her to remove her hijab in front of him, because he is not a mahram (a relative one may not marry) for her. She may only remove her hijab in front of her mahrams, and he is not one of her mahrams. Growing up with him does not make him a mahram for her. Yes.