Without Honor (1949) on Netflix

Plot summary

Jane Bandle, a housewife, is at home when Dennis Williams, the married man she has long been involved with, comes to end their affair. She threatens to kill herself; she reaches for a shish kabob skewer, a struggle follows, and the skewer is driven into Dennis's chest. He collapses, and Jane hides his body inside the house. Before she can go, her brother-in-law Bill Bandle arrives and says he knows about the affair and has asked her husband Fred, Dennis and Dennis's wife Katherine to her home that evening, where he intends to tell them. Jane wants to get away before they arrive, but Bill will not let her leave.