What is the ruling regarding a husband who spends only a little on his wife and infant son, and demands that she spend from her family or her salary, and treats her poorly, and threatens her with taking her son if she asks for a divorce, while he spends on his unneedy family who exploit him and incite him against his wife? And what is the ruling on the wife seeking a divorce in this case?

Marriage is built upon affection and love. This husband is negligent in his duties towards his family and his Lord. He needs advice and reminding of the prohibition of cursing, watching obscene films, usurious loans, restricting his wife, and depriving her of her right to maintenance. It is permissible for a wife who is harmed by her husband to seek a divorce if he mistreats her, or falls short in maintenance or marital rights. She does not fall under the threat mentioned in the Hadith (definition), and the custody of an infant remains with its mother. The solution is either patience while striving to reform him, or seeking a divorce while taking all her rights and custody of her son, or a khul' (divorce by mutual consent) by forfeiting her Mahr if he refuses to divorce.