I remember the story vividly, except for the title, author, or character names that would let me pull it up in a search.
Deceased next door neighbor's housekeeper approaches neighbor with proposal to marry him for a green card. Housekeeper is Asian, maybe Philipino, and her name starts with a P--- Pera, Pena... something like that. She makes a great wife in terms of keeping the house, making the budget stretch, etc, but she is saving herself for a fisherman back home so vaginal sex is off the table.
Neighbor falls in love with her but knows that once she has her green card she'll be gone. Time goes by and she asks him to sponsor her mother and sister as well, and they come to live with him. Eventually the woman realizes she has been hung up on a fantasy marriage with the fisherman when she's already in love with her real husband in the US.
I've read this story two or three times now and should have bookmarked it.