ANSWER: 

Of course not.
He’s your mahram for life.
A son in law is a mahram to a woman even if the daughter dies or they get divorced. 

Do we have to observe pardah (hijab) From our son in law ? ( daughter’s husband )

Mahram | January 11, 2018 1:12 am
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My grandmother remarried when my real grandfather died. So,is my father’s step father or my step grandfather my mahram? Also are my step grandfather’s sons my mahram?
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Is it permissible for the married brothers along with their wives and children to join in a single kitchen and to have common washrooms? Is my uncle’s wife mahram to me?