I think this is one of the biggest divergences between what women think men care about and what they actually care about. Men do not give a single crap about stretch marks.
Or as a commenter said:
Was having sex with a woman back when I was in the army who said, “Sorry about my stretch marks” and I replied, “I don’t mind at all” when in reality I didn’t even see them or notice them. So of course I didn’t mind because I had no damn idea about any stretch marks that might or might not have been there.