Thor doubted that she could be plesant enough for the both of them. He didn't respond, but eventually stopped stabbing at the logs in the hearth. It was a suitable fire now. The flames cast a warmth throughout the small interior of the cabin, directly in contrast to the unforgiving cold of the ice and snow outside.
He appreciated that she was allowing him the freedom of his reactions, without judgement; and without appearing to be afraid either. Which was very good. If she acted as though she feared him, it would have cut into him with a hurt that went as deep as betrayal. She was family, and he could never dream of harming his family. The thought itself would have sickened him. He'd considered Loki his family, before all this. Not anymore. His temper and unchecked emotions were overbearing and exhausting to be on the receiving end of, he realized that with some clarity. But he tried to justify it as simply the intensity of his devotion to those he loved. He loved Sif so desperately that he could barely function now, knowing all of it had been a lie.
He was hardly aware of Idun as she searched about the cabin, preparing something. It was only when she moved into his range of vision directly; placing the small kettle into the hearth; that he finally spoke. "I apologize that this cabin is not better... stocked. I hadn't thought to.. " He trailed off. It didn't really matter.
The silence that followed began to feel different. She was making no demands of him. Just sharing in this moment, even though it must have been uncomfortable; to say the least. Her presence began to ease into him like a soft light, slowly guiding him back from the brink of his fury. She did not expect anything from him, and he found that incredibly welcome, in his current state. Normally, he liked others to expect things from him. He liked to be useful, to be needed. It made him feel worthy. Strong. He could handle the demands and expectations of others because he had very much of himself to give. His strength and his heart had few limits. But right now, he doubted that ability to give; and he hated it.
Then she broke the silence. And her words were too much. Too much all at once, each one hitting him with a different kind of shock. The small amount of calm that settled over his body evaporated immediately.
He turned to face her, voice raised in disbelief. "What?! Before we were-- for how long?"
He didn't give her time to answer before the rest spilled out abruptly. "But she didn't choose me, did she?!" He was louder now, unable to control his volume. "She chose to be with him, all the while we were together; behind my back... humiliating me, and you... You knew? Why... didn't you tell me, Idun? Did you think it wouldn't matter? Was she in love with him the whole time?"
He was unable to comprehend anything right now. This was why he hadn't asked for details from Sif. He knew he couldn't handle anything she would have told him. For all his strength and all his might, he couldn't seem to stop his voice from sounding like a lost young boy towards the end of his tirade; nothing at all like the fierce and relentless warrior he had built himself to be. He was an emotional mess, and this is why he had hidden himself away from the ones he loved, he couldn't bear to show them how truly weak he could be. He was a protector of men, a champion of Asgard. He was not meant for this.