Does Julia betray Winston?

Julia does betray Winston in 1984, though her betrayal happens under torture rather than through voluntary spying for the Party. Their affair begins with Julia secretly slipping Winston a note that says "I love you." For a time, their relationship seems like the one private loyalty the Party cannot reach, but that belief is destroyed after they are arrested in the room above Mr. Charrington’s shop. The hidden telescreen repeats their own words back to them, "You are the dead," and the Thought Police beat Julia and carry her away. In the Ministry of Love, O’Brien tells Winston that Julia has betrayed him and submitted to the Party quickly through torture.

Julia later confirms this when she and Winston meet after their release. She explains that the torturers threaten a person with something unbearable, until the victim says to give the punishment to someone else. Her explanation is blunt: "All you care about is yourself." Winston answers by echoing her words, and they both understand that the betrayal was real because, in the moment, each truly wanted the other person to suffer instead.

Winston’s own betrayal is shown directly in Room 101. Faced with the threat of starving rats gnawing at his flesh, his greatest terror, he cries, "Do it to Julia! Do it to Julia! Not me! Julia!" That moment breaks the last bond he had tried to preserve. Earlier, he had believed that the Party could torture or kill them without changing their love. But afterward, he and Julia no longer desire each other and part with no real intention of meeting again.

Julia and Winston's betrayals of each other show how the Party’s power reaches beyond forced confessions into the kind of private loyalties that made their rebellion meaningful. Their love threatens the Party because it gives them a loyalty outside Big Brother, and Room 101 destroys that loyalty by making self-preservation stronger than love.