Alec loved life with Magnus in Alicante. By mundane standards their wedding might have been rather premature, but Shadowhunters never knew if they'd still be alive tomorrow, and their relationship had only gotten stronger since. Plus, Alec got to make a real difference, bringing some long-overdue change to the Clave.
So when one night Magnus welcomed him home not with his customary cocktail but with a packed bag that was much too unadorned to belong to the warlock, Alec stared at him in confusion. "Magnus?"
"Alexander, I love you dearly," Magnus stated very slowly, as if Alec was being particularly dense, "but this has got to stop."
"What?" Alec interjected, but Magnus shushed him with a fingers against his lips.
"Don't forget that I know you. All of you." The smile on Magnus's face was warm, and as always Alec relaxed, trusting him. "And that includes that pesky parabatai of yours."
"Jace?" Alec asked dumbly. "I've invited him to come visit, but he doesn't want to leave Clary."
"Of course, and I understand. Biscuit's all alone, and he needs to make sure she's okay." Magnus's eyes darkened with sorrow over Clary's fate, and Alec pulled him into a hug. Magnus allowed it, but still continued, "That's why you need to go to him. And not just because he needs you, but because, no matter how hard you've been pretending that you're doing great without him, you need him, too."
Alec hid his face in Magnus's hair, grateful that his husband couldn't see his face, protesting, "I love you, Magnus; I love our life here."
It wasn't denial, and they both knew it. In response, Magnus kissed him gently, pressing his bag into his hand. This time Alec accepted, a part of him already back in New York. Back with Jace.