Fandom: The Mortal Instruments
Pairing: Magnus/Alec
Prompt: Magnus getting jealous of Jace with Alec.
It was obvious from the moment Magnus saw them together that Alec harbored illicit feelings for his parabatai, Jace Wayland, and for the life of him, Magnus couldn't see what there was to like, but to each his own. It didn't bother him much in the beginning because he knew Alec's feelings weren't returned and, well, things were still so tentative between himself and Alec. At first, it was even easy to ignore the secretive glances and chaste touches, but the closer he got to Alec, the more his feelings for Jace started to grate on Magnus' nerves. It wasn't until he decided to drop in unexpectedly – because, otherwise, Alec wouldn't agree to it since he still hadn't told his family about them – to visit Alec, that Magnus realized just how much Alec's feelings for Jace bothered him.
After a quick pet, Church led Magnus to the Institute's library where the Lightwood children were gathered. Isabelle and Max were sitting at a table; she was pointing at and explaining something out of the book that was open in front of them. Max's eyes were wide as he studied the pictures, the expression was so innocent Magnus couldn't help but grin. His golden eyes moved over the rest of the room, searching for Alec. Magnus froze, his body tensing when he found his Shadowhunter.
Alec lay on one of the couches that had been placed near the large fireplace, his head resting propped up on Jace's leg as he slept. It wasn't the position that bothered Magnus, he knew how close the two were and he had found them sitting like this before. No, it was Jace's fingers… they were idly carding through Alec's black hair, over and over. The action was unconscious to Jace, whose mind was occupied by what he was reading, the book held in his free hand. There was just something so intimate about the gesture that it made Magnus clench his teeth.
Magnus turned on his booted heel, his bright yellow trench coat flaring out as he left the library without a word. Isabelle cleared her throat and caught Jace's eye. Jace sighed and closed his book before nudging Alec's shoulder. Alec groaned softly at having his nap disturbed, he yawned and blinked slowly up at his parabatai. He was about to ask why Jace had woken him when Max spoke.
"That was Alec's warlock right?"
Alec's eyes widened and he sat up quickly. "Magnus was here?!" Then Alec realized that Max had called Magnus his. "He's not—we're not—I—"
"Complete in a bright, glittery, neon yellow trench," Isabelle answered.
Jace opened his book back up, returning to the page he had been on. "Go after your boyfriend," he said quietly. Alec turned to him, his blue eyes wide. Before Alec could start to argue, Jace spoke again. "Go."