The mahram status of one who was breastfed by the maternal grandmother of his mother’s daughters

Question:
One of the female listeners sent a message containing several questions, identifying herself by the initials (A. F). She says: I have a cousin (son of my father’s sister). His mother passed away while he was still a small child. Then my grandmother, my father’s mother—who is his maternal grandmother—breastfed him along with one of my aunts. My question is: Is he a mahram to us, such that it is not permissible for us to marry him? Since he was breastfed with my aunt, does that make him her brother and her sister’s son? Please note that I cover myself in his presence until I know the ruling.

Answer:
If the breastfeeding was lawful, consisting of five times or more, while he was an infant who had not been weaned before the age of two, then he becomes your paternal uncle. He becomes your father’s brother and a mahram to you, because your grandmother, your father’s mother, breastfed him. He becomes your paternal uncle and the paternal uncle of all your father’s children, provided the breastfeeding was five times or more within the two-year period before weaning. However, if the breastfeeding was less than that, or occurred after weaning, it has no legal effect, it does not impact the ruling, and he does not become your paternal uncle. Yes.

The presenter: May Allah reward you with good. So, she must verify the details of the breastfeeding, and at that time...?

The Shaykh: Yes.

The presenter: May Allah reward you with good.