Lost story

Looking for a story by an American short story author. Main character lies in bed beside his sleeping wife. He fantasizes about a woman he sees across the street going in and out of her apartment. When he finally sees her in person, she is old and he is shattered.

Hi and welcome to Librarything! You'll probably find the answer you seek in our Name That Book! group, where they specialize in finding lost titles:
https://www.librarything.com/groups/namethatbook

Please be sure to read the group's header for instructions on posting your request, and click the Post New Topic directly below this header.