Quote 1
"I betrayed you," she said baldly.
"I betrayed you," he said.
She gave him another quick look of dislike.
"Sometimes," she said, "they threaten you with something you can't stand up to, can't even think about. And then you say, ‘Don't do it to me, do it to somebody else, do it to So-and-so.’ And perhaps you might pretend, afterwards, that it was only a trick and that you just said it to make them stop and didn't really mean it. But that isn't true. At the time when it happens you do mean it. You think there's no other way of saving yourself, and you're quite ready to save yourself that way. You want it to happen to the other person. You don't give a damn what they suffer. All you care about is yourself."
"All you care about is yourself," he echoed.
"And after that, you don't feel the same towards the other person any longer."
"No," he said, "you don't feel the same." (3.6.16-22, Winston and Julia)
For both Winston and Julia, torture is able to chew through the deepest bonds of loyalty.
Quote 2
"You are the dead," repeated the iron voice.
"It was behind the picture," breathed Julia.
"It was behind the picture," said the voice. "Remain exactly where you are. Make no movement until you are ordered."
It was starting, it was starting at last! They could do nothing except stand gazing into one another's eyes […] unthinkable to disobey the iron voice from the wall. There was a snap as though a catch had been turned back, and a crash of breaking glass. The picture had fallen to the floor uncovering the telescreen behind it. (2.10.21-24)
Winston and Julia come to a rude awakening when it turns out that their rented room has a hidden telescreen that has surveyed them for their entire affair.
Quote 3
"I've been at school too, dear. Sex talks once a month for the over-sixteens. And in the Youth Movement. They rub it into you for years. I dare say it works in a lot of cases. But of course you can never tell; people are such hypocrites." (2.3.24, Julia)
Female Party members have been brainwashed since childhood about the importance of chastity as manifestation of one’s loyalty to the Party.