She threw the door open. The room seemed to be a sort of library, the walls lined with books. It was brightly lit, light streaming through a tall picture window. In the middle of the room stood Jace. He wasn't alone, though-not by a long shot. There was a dark-haired girl with him, a girl Clary had never seen before, and the two of them were locked together in a passionate embrace
Cassandra ClareI was trying to make you jealous!" Simon screamed, right back. His hands were fisted at his sides. "You're so stupid, Clary. You're so stupid, can't you see anything?" She stared at him in bewilderment. What on earth did he mean? "Trying to make me jealous? Why would you try to do that?" She saw immediately that this was the worst thing she could have asked him. "Because," he said, so bitterly that it shocked her, "I've been in love with you for ten years, so I thought it seemed like the time to find out whether you felt the same about me. Which, I guess you don't.
Cassandra Clare