Serious Damage, by Cathryn Grant, almost had a Poe-like quality, as the reader learns about two women competing for the same man. Or are they? Melinda learns that coworker Caroline has a reputation for being delusional. "She's in her own world," other coworkers say of Caroline. When Caroline drops the bombshell that she's having an affair with Melinda's boyfriend, Melinda doesn't believe her. The storytelling is in the moment, emotionally intimate, and from Melinda's somewhat unreliable point of view.
The Magnolia Murders, by O'Neil De Noux, involves infidelity in the past tense. In fact, the story is told as a flashback, opening with a question, telling the story, and ending where it began - with an answer to the question. Wealthy businessman Franklin Fortesque VII is running for governor. He hires private detective Lucien Caye to solve two murders, and thus clear the path for his campaign. The problem is, the deceased are Fortesque's wife and her lover. In this story, the narrator is emotionally removed from the infidelity. He sympathizes with the star-crossed lovers. The case appears to have no solution, until Caye interviews the only witnesses, a stuttering little girl clutching a kitten, and Elvira the Goat Lady.
Good storytelling can take a well-used theme and make it fresh. Both authors succeeded with these stories.