The sibling tension between Peter and Fudge reveals annoyance and love.
Fudge frustrates Peter. As a nine year old, Peter seeks to establish his own voice. Fudge challenges this with his antics. Peter notes this early on in the narrative:
"Fudge is always in my way. He messes up everything he sees. And when he gets mad he throws himself flat on the floor and he screams. And he kicks. And he bangs his fists."
Peter strives for quiet when he sleeps. However, Fudge talks and makes noises while he slumbers. Finally, Fudge enjoys making noises that Peter finds annoying: "And that's one of his favorite pastimes-banging pots and pans together. A person can get an awful headache listening to that racket." Peter finds it very difficult to live with Fudge.
However, it is also clear that Peter loves his brother. One example is in how he endures what Fudge does. He does not abuse Fudge. Rather, he understands that Fudge has much to learn and tolerates his antics. Peter's patience shows love. Peter also recognizes that he is a role model. Fudge tries to imitate Peter. His annoyance is an alternate way of communicating the respect he has for his older brother. As seen with the saddle shoes and tricycle, Peter embraces this. Peter's positive and negative experiences with Fudge represent the essence of sibling rivalry.