Is it permissible for me to uncover my hair in front of my husband's paternal uncle?

It is not permissible for a woman to uncover her hair or any part of her body in front of her husband's paternal uncle, unless there is a prohibited degree of kinship between them by blood or suckling, because he is considered a non-mahram (definition). The Prophet, peace and blessings be upon him, emphasized the seriousness of mixing with the husband's non-mahram relatives, saying: "Beware of entering upon women." And when he was asked about the hamw (male in-law, like the husband's brother or paternal uncle), he said: "The hamw is death!" due to the tribulations that can result from such interaction.