Lady Macbeth is anything but diplomatic in this scene. She berates her husband for being weak. Macbeth starts the scene by making the decision to not do anything to King Duncan; he has been wavering about whether or not to act against the king ever since he realized the witches' prophecies might be right. When Lady Macbeth comes into the scene and he tells her he doesn't want to do anything to the king, she immediately gets angry with him. She asks him why he told her about the prophecies to begin with if he wasn't going to try to expedite matters. Then she accuses him of being "...a coward in thine own esteem;" adding that he is hiding behind his wimpy fears. She goes on to tell him that she has the strength of will to do it, in fact, she says, if she'd sworn to someone to perform an act, she'd follow through with it even if it meant taking her nursing child from her breast and throwing it to the floor. She attacks her husband in his most vulnerable area - his masculinity and it works. He gives into her and agrees to kill King Duncan.