Here’s a free book idea. There are, as I see it, three basic ways this could go.
Happy couple and two children are on vacation at the beach. Husband excuses himself to go into the cabin to tinkle. Instead, he gets on the phone to his mistress and reaches her voice mail. “Hey, it’s me. I’ve finally decided. I’m going to tell her as soon as we get home. I can’t stand it any more. It’s what you’ve been asking me to do. So, anyway, see you on Saturday. Love you.” Then he stares thoughtfully out the window at the children happily playing and the surf eternally crashing.
Around the time he’s saying “I’ve finally decided,” the wife follows him in and stops short in the doorway. He doesn’t hear her or doesn’t notice, so she listens and waits until he hangs up. There are three ways this could go from here. . . .
(1) The screaming harridan. The woman picks up something and hurls it at him without asking for any explanation. “Liar! Cheat!” She throws his clothes out and ends the vacay right there. You know the drill from here.
(2) The woman goes into the kitchen/bar while he is standing post-call to stare out the window into the distance at the kids making a sand castle. She makes a tray with two glasses and a pitcher of “martinis,” but the martinis have hemlock in them. (Maybe curare, too, just for the paralysis factor.) (You’ll have to set up how she got this stuff . . . maybe she’s an herbalist.) She carries it in and says loudly, “Tell me what?”
He spins around guiltily and knows he’s been made. He walks over to slug down the first drink to steel himself. She sets the tray in front of him on the table and sits down. “I’m listening.”
By the time he is halfway through his story, she knows it’s working and he knows there’s something wrong, but attributes it to the booze. The reason they used hemlock for executions in ancient times is that it allows lucidity up until almost the end. She’s well rid of the guy. . .and gets to sue the resort for his death, to boot (if they prefer to hush it up instead of thinking it’s murder).
(3) The woman hears, but does nothing. For now. This is the tale of the She-Devil who will ruin him without his even knowing until the end. This is the far more interesting story.
Let’s see what you can do with it.