The son of a man's stepmother marrying his sister

Q 3: My father married a woman who had a child. She bore him two daughters and then she passed away. My father married another woman who bore him sons and daughters. My father's step-son was brought up in his house. Is it permissible for him to marry one of my sisters? Is it permissible for him to inherit my father?

A: If the matter is as you have described, it is permissible for the step-son to marry one of your sisters but it is not permissible for him to inherit your father. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.