In the beginning of the play, Macbeth and his wife are very intimate and close to each other. Later on, however, the two characters become distant, keeping secrets to themselves. Significant scenes throughout the play of "Macbeth" that set the tone of the couple's relationship include Act 1 Scene V, Act 1 Scene VII, Act V Scene I and Act V Scene V. By the end of Act 1, after the brutality of what they have committed, the relationship is completely destroyed, giving way only to loneliness, coldness and insanity. Harold Bloom, an American literary critic, says that Macbeth and Lady Macbeth's relationship is the "best marriage in Shakespeare" at the beginning of the play, equal in love and ambition. Duncan calls Macbeth's affection "sharp as his spur," while Macbeth calls his wife "dearest partner of greatness" and "dearest love.".
In Act 1 Scene V, as they plan the murder of King Duncan, it is Lady Macbeth who convinces her husband to commit the crime. She believes that Macbeth alone is not capable of murdering Duncan. Macbeth is 'too full o' the milk of human kindness" to commit such a deed. According to Lady Macbeth, there is no "illness" or badness in his personality. In order to become king, a title that he would like to be, he would have to murder, but he is too kind and decent to do so. Lady Macbeth therefore intervenes and plots to kill Duncan. This plot introduces tension into the relationship between Macbeth and Lady Macbeth. Lady Macbeth becomes so fond of the idea of becoming Queen of Scotland that she mocks her husband by questioning his masculinity and saying that she would stop at nothing in order to get what she wants and she would never break a promise; "How tender 'tis to love the babe that milks me: I would, while it was smiling in my face, have pluck'd my nipple from his boneless gums, and dash'd his brains out, had I so sworn as you have done to this".