Act 3 of Macbeth is the last point in the play where Macbeth and his wife are seen together interacting, only to reappear together all the way in Act 5. This is due to a dramatic shift in the relationship between the 2 characters, seemingly sometime after taking on the throne. One interpretation of this may be due to the fact that Macbeth has been put into a position of significant power above his wife and everybody else, therefore doesn’t feel the need to rely on his inferior for guidance. As a result, their relationship appears to be a lot less open, for instance when he reminds Lady Macbeth to “Let your remembrance apply to Banquo”. (3. 2. 32-33) It has been confirmed here that Macbeth hasn’t yet informed his wife of his plans/scheme to murder Banquo. The roles of power have essentially reversed and can be inferred that Macbeth is trying to prove his independence and competence to Lady Macbeth who usually dictates action.
In addition to this, ever since the initial plotting to murder King Duncan, there has been rising tension between the couple with every obstacle placed in their way. Rather than overcoming these together through marital support, each one (in particular Lady Macbeth) has resorted to personal character assassinations and criticism – most likely a response to fear and frustration. One example of this is the continuous labelling Mabeth as a wimp, eg. “Are you a man?” (3. 4. 61-62), subsequently followed by “Oh, these flaws and starts, Impostors to true fear, would well become A woman’s story at a winter’s fire, Authorized by her grandam.” (3. 4. 66-69).
Although both characters shared the same initial goals/aims, once they arrived where they strived to be (on the throne), Macbeth only pines for more. This is displayed in Lady Macbeth’s aside where she expresses “Naught’s had, all’s spent, Where our desire is got without content.” (3. 2. 6-7). Essentially, after all the pair of them have been through, Macbeth is still displeased and anxious, not to mention increasingly distant from her. This appears to frustrate Lady Macbeth as he keeps creating new dilemmas through his behaviour, for example, when she stated he had “displaced the mirth, broke the good meeting, With most admired disorder.” (3. 4. 13) When they once they called each other “dearest partner of greatness” (1. 5. 3?) they now take their emotions out on each other which ultimately divides the two.
As a whole, one may decipher that the couple drift away from each other for an extended period of time, as a result of a few primary points. These include being less honest or open with each’s intentions/plans, constant deterioration of each’s profile (especially Macbeth’s), taking anger out on each other, lack of support, a reversal of power roles, and Macbeth’s insatiable need for more to be done.