David is trying to abide by the proverb ‘revenge is a dish best served cold’ – meaning take your time in avenging a wrong, it will be all the more effective and enjoyable. But he is having trouble because he has trouble with “delayed gratification.” That is the psychological process that occurs with maturity, of realizing that you can’t always get what you want immediately. Maturity and David are not yet on a first-name basis.
He is trying. It’s been a few weeks since he found out about Kylie’s one-night-stand with Nick and the fact that she is not sure about the paternity of the baby she is carrying. He decided to take his revenge on Nick, not her. As he said to Tina, he can’t risk losing Kylie and, once he confronts her about her infidelity, he won’t be able to forget what he knows. Of course he can’t forget it anyway. So he is displacing his anger: instead of destroying his own marriage, he will destroy his brother’s. It’s working, but not quickly enough for David to keep his composure.
He finds a second repository for his anger, his mother. In an absolutely frightful scene, David amuses himself and exorcises his demons by tormenting his mother. Starting with snide remarks while Gail makes their dinner and he eats peanuts, he moves on to throwing peanuts at her. In a ghastly escalation he physically moves in on her, still holding the bag of peanuts and still chucking them one by one, hitting her face and upper body. He laughs while he’s doing it, demanding she play catch with her mouth, but Gail is frightened by the twisted brutality he shows her in his “fun”.
The camera stands in David’s place as he backs her into the kitchen cupboards. We see what he sees, his mother’s face wrenched in terror. I fully expected to see her hand search for a knife on the countertop, any weapon to stop him coming at her, pushing her farther and farther into the corner. And the camera switches so we see as Gail sees – an enraged yet cold attacker-son coming at her relentlessly.
The game of terror stopped after Kylie’s entrance to the kitchen to see what was going on. Just a bit of fun, according to David, just relieving some stress. A very weak apology and explanation to his mother, at Kylie’s insistence; stressed out over money, working too hard, anxious about the new baby. Kylie is frightened, but willing to buy it for the sake of peace. Gail – not so much. She has seen Psycho Dave’s violence before. She has been his victim before. Despite her usual willingness to overlook and explain his patent lunacy, she is too shaken by this. She leaves the house for the safety of Sally’s. If I were Kylie, I’d be right behind her!
There is another saying David might want to remember: “Before you embark on a journey of revenge, dig two graves.” David will be his own worst enemy in exacting a slow revenge, pleasurable and safe for himself if no one else. He will, I think, destroy not only Nick’s marriage but his own and his relationship with his mother. He will destroy himself as well. He does not have the degree of self-control, or introspection, necessary to be an effective Machiavelli and make others suffer while he prospers.