Shannon

“While this is all very amusing, the kiss that will free the girl is the kiss that she most desires,” she said. “Only that and nothing more.”

Jace’s heart started to pound. He met the Queen’s eyes with his own. “Why are you doing this?”

… “Desire is not always lessened by disgust…And as my words bind my magic, so you can know the truth. If she doesn’t desire your kiss, she won’t be free.”

“You don’t have to do this, Clary, it’s a trick—” (Simon)

...Isabelle sounded exasperated. ‘Who cares, anyway? It’s just a kiss.”

“That’s right,” Jace said. Clary looked up, then finally, and her wide green eyes rested on him. He moved toward her... and put his hand on her shoulder, turning her to face him… He could feel the tension in his own body, the effort of holding back, of not pulling her against him and taking this one chance, however dangerous and stupid and unwise, and kissing her the way he had thought he would never, in his life, be able to kiss her again. “It’s just a kiss,” he said, and heard the roughness in his own voice, and wondered if she heard it, too.

Not that it mattered—there was no way to hide it. It was too much. He had never wanted like this before... She understood him, laughed when he laughed, saw through the defenses he put up to what was underneath. There was no Jace Wayland more real than the one he saw in her eyes when she looked at him… All he knew was that whatever he had to owe to Hell or Heaven for this chance, he was going to make it count.

He...whispered in her ear. “You can close your eyes and think of England, if you like,” he said.
Her eyes fluttered shut, her lashes coppery lines against her pale, fragile skin. “I’ve never even been to England,” she said, and the softness, the anxiety in her voice almost undid him. He had never kissed a girl without knowing she wanted it too, usually more than he did, and this was Clary, and he didn’t know what she wanted. Her eyes were still closed, but she shivered, and leaned into him — barely, but it was permission enough.

His mouth came down on hers. And that was it. All the self-control he’d exerted over the past weeks went, like water crashing through a broken dam. Her arms came up around his neck and he pulled her against him… His hands flattened against her back... and she was up on the tips of her toes, kissing him as fiercely as he was kissing her... He clung to her more tightly, knotting his hands in her hair, trying to tell her, with the press of his mouth on hers, all the things he could never say out loud...

His hands slid down to her waist... he had no idea what he would have done or said next, if it would have been something he could never have pretended away or taken back, but he heard a soft hiss of laughter — the Faerie Queen — in his ears, and it jolted him back to reality. He pulled away from Clary before he it was too late, unlocking her hands from around his neck and stepping back... Clary was staring at him. Her lips were parted, her hands still open. Her eyes were wide. Behind her, Alec and Isabelle were gaping at them; Simon looked as if he was about to throw up.

...If there had ever been any hope that he could have come to think of Clary as just his sister, this — what had just happened between them — had exploded it into a thousand pieces... He tried to read Clary’s face — did she feel the same? … I know you felt it, he said to her with his eyes, and it was half bitter triumph and half pleading. I know you felt it, too…She glanced away from him... He whirled on the Queen. “Was that good enough?” he demanded. “Did that entertain you?”

The Queen gave him a look: special and secretive and shared between the two of them. “We are quite entertained," she said. “But not, I think, so much as the both of you.”
― Cassandra Clare, City of Ashes