And the little bird, your pretty sister, I stood there in my white cloak and let them beat her. I took the bloody song, she never gave it. I meant to take her too. I should have. I should have fucked her bloody and ripped her heart out before leaving her for that dwarf.
Yes, i know that quote and the fact that you can see how much Sandor was destroyed in the mind and the spirit when he said it.
"Don't lie," he growled. "I hate liars. I hate gutless frauds even worse. Go on, do it." When Arya did not move, he said, "I killed your butcher's boy. I cut him near in half, and laughed about it after." He made a queer sound, and it took her a moment to realize he was sobbing. "And the little bird, your pretty sister, I stood there in my white cloak and let them beat her. I took the bloody song, she never gave it. I meant to take her too. I should have. I should have fucked her bloody and ripped her heart out before leaving her for that dwarf."
(A Storm of Swords - Arya XIII)
Sandor was sobbing AND NOT FOR THE PAIN.
He was in the same painfull conditions when he said that he did not care for the little butcher's boy, he growled but he did not cry.
Its for Sansa that he cried, he never once pretended to be a better man that he was nor he pretend to no being guilty and wrong for that attraction that he has for Sansa, instead he compare make Sansa cry to a sin equal if not worse than kill a boy.
He even compare saving Sansa to his only reediming quality and he romanticize her as she does for him :
"Because I hacked your little friend in two? I've killed a lot more than him, I promise you. You think that makes me some monster. Well, maybe it does, but I saved your sister's life too.
The day the mob pulled her off her horse, I cut through them and brought her back to the castle, else she would have gotten what Lollys Stokeworth got. And she sang for me. You didn't know that, did you? Your sister sang me a sweet little song."
(A Storm of Swords - Arya IX)
Sandor is not a perfect prince, none is in that books and Sansa knows it better than anyone since perfect prince Joffrey revealed himself for the monster that he is, but Sandor showed to deeply care about Sansa and to perceive his wrong actions against her as his biggest sin.
Sandor's intentions werent pue but if he wanted to rape her he would, he restrain himself because he knows he deeply care about Sansa and he devoted to her enough to try at least to change.
Its more evident if you compare how Sandor react to Sansa's refuse in opposition to Tyrion :
His mouth jerked as if she had slapped him. "Never?" Her neck was so tight she could scarcely nod. "Why," he said, "that is why the gods made whores for imps like me."
(A Storm of Swords - Sansa III)
The room was too dark for her to see him, but she could feel the stickiness of the blood, and a wetness that was not blood.
"Little bird," he said once more, his voice raw and harsh as steel on stone. Then he rose from the bed. Sansa heard cloth ripping, followed by the softer sound of retreating footsteps.
(A Clash of Kings - Sansa VII)
Sansa had to openly reject Tyrion to get him away form her and even then he is frustrated as if he was misreated, Sandor get away from her because he felt ashamed. We can see that both are aware of their attraction but Sandor is ashamed.
"You look almost a woman...face, teats, and you're taller too, almost [..] Do you like wine, little bird? True wine? A flagon of sour red, dark as blood, all a man needs. Or a woman." He laughed, shook his head. "Drunk as a dog, damn me. You come now. Back to your cage, little bird. I'll take you there. Keep you safe for the king." The Hound gave her a push, oddly gentle, and followed her down the steps.
(A Clash of Kings - Sansa II)
Tyrion had commanded Sansa to wear a sleeping shift as well. I want her, he realized. I want Winterfell, yes, but I want her as well, child or woman or whatever she is. I want to comfort her. I want to hear her laugh. I want her to come to me willingly, to bring me her joys and her sorrows and her lust.
(A Storm of Swords - Tyrion IV)
She covered her breasts with her hands. "I've flowered."
"A child," he repeated, "but I want you.
Does that frighten you, Sansa?"
"Yes."
(A Storm of Swords - Sansa III)
Sandor also has a deep devotion to Sansa, so much so that while Jon was totally indifferent to Sansa being forced to marry Tyrion, Sandor was praying to see Sansa killing Tyrion to save herself :
Sansa only knows songs, not spells, and she'd never marry the Imp. The Hound sat on the bench closest to the door. His mouth twitched, but only the burned side. "She ought to dip him in wildfire and cook him. Or tickle him till the moon turns black."
(A Storm of Swords - Arya XIII)
"The little bird flew away, did she? Well, bloody good for her. She shit on the Imp's head and flew off."
(A Storm of Swords - Arya XIII)
the second quote is so funny to me, because he was able to answer to Sansa aka the girl that had the whole kingdom calling her a regicide but only cared about Sandor still being on her side :
She wondered what had become of Sandor Clegane. Did he know that they'd killed Joffrey? Would he care?
He had been the prince's sworn shield for years.
(A Storm of Swords - Sansa VI)