What is your opinion on a person who is very strict with his sisters, to the extent that he cut ties with one of them for five months because she spoke with men (her friends), while he later married a woman of bad character who commits acts close to what is forbidden and has relationships with men, and he is aware of this?

A brother's protective jealousy over his sister is obligatory, for she is his honor that he must preserve and defend. Jealousy is a sign of faith. Paradise has been forbidden to the dayyūth (pimp or panderer), who condones indecency among his family. This action from the brother is legitimate and obligatory, and his silence regarding his wife is incorrect and forbidden. There is no friendship between men and women in Islam; the general principle is separation between them. The brother must advise his wife and rebuke her from forbidden acts by all means, and if she does not reform, a Muslim should not be content to keep a wife with such character.