Maybe he walked out to get some cigarettes.
Hasn’t returned for five years.
An example of a story in the recorded lectures by Dwight V. Swain called Master Writing Teacher (author of Techniques of the Selling Writer and many others including suspense and SF).
A man goes out and tells his wife he’ll be right back. Never returns for almost a year. No word. No asking for a divorce.
Suddenly, one night he comes home again, holds up his hand and refuses to talk about it. She goes along.
That night he quietly into bed and they still don’t talk.
As he falls asleep, she takes out the long blade from under her pillow and slashes his throat.
That sounds like an episode of Alfred Hitchcock or something written up E. Hemingway. She was pushed too far. Her Mask of nonchalant compliance fell to the linoleum floor and quietly ignited. She washed the blade at the sink. finding it difficult to stop laughing.