Breastfeeding an older child so that the woman becomes his mother

The questioner:
My question, my brother, is about a boy we took from the orphanage. We took him from the orphanage in the year 2000, or 2001, or 2002, about fifteen years ago. The boy is fifteen years old. I married a second wife, and she has borne me children, and my second wife is currently breastfeeding. So, does this boy, who is still in the first year of secondary school, count as a mahram (a relative one may not marry) to this woman so that it can be written on their documents?

The Shaykh:
No, my brother, he is an adult. He is an adult and does not need breastfeeding, so do not breastfeed him. Yes.

The questioner:
Thank you, may Allah bless you. There is a book by Ibn Uthaymeen (may Allah have mercy on him). My brother, listen, may Allah guide you.

The Shaykh:
Definitely.

The presenter:
The Shaykh has already answered you on this.

The Shaykh:
My brother, listen, may Allah guide you. Yes.

The presenter:
May Allah reward you with good.