Almost certainly the same guy. 131279 is almost the same setup as the first chapter and she has the same name. Plus the tag line says "arafo- hitozuma Ayano" which means "a 40ish housewife Ayano" and goes on to say that she had forgotten what it meant to be a woman but became a sex friend (the Japanese is quite a bit more explicit) of her son's friend. I think you solved what many readers here were asking about...