Deep Water

Classic Highsmith! Most of her novels form the same pattern, a happy couple in wealthy, small town America where the husband ends up murdering someone unexpectedly and usually with good motive (self defence or a sudden blow dealt after great provocation). The murderer is increasingly suspected but the evidence doesn't exist and, as always, you root for them, wanting them to get away with it which they may or may not do.
Here, the husband has a promiscuous wife who flaunts her boyfriends in his face. He patiently endures it until he snaps and pulls one of them under the water of a swimming pool one night. She knows he's done it but there is no evidence. Always people drink Scotch (Highsmith's tipple) and the lunches and breakfasts they eat are described and so it is here. Always worth reading.