Notes: Written by a word prompt on tumblr.
Jace had never been able to understand the supposedly proven myth that once a couple got married they started fighting much more often, but he was willing to admit that it probably applied to parabatai.
Everyone was trying to act as if nothing had happened. There was small talk around the table and everyone was polite and quiet and did their very best to ignore the ever growing tension, but it wasn't easy.
The amount of attention Alec was giving to his food would have been suspicious all on its own even to a stranger, but to Jace, it was a sure sign that he was furious. He was containing his emotions completely just as he always did, but it was clear that it was taking a lot more effort than usual. The fight they'd had earlier that day had turned out to be the worst one so far and it had happened in the middle of a hallway, so half of the Institute had been treated to every detail of their screaming match. It had started out as something rather innocent – Alec's refusal to assign himself and Jace a mission that Jace had wanted to get and that had been ultimately turned into one of Alec's first trials in decision making as Head of the Institute – and had progressed into something much worse; something that neither of them really wanted to discuss.
And they didn't have to – not now, at least. Almost every Shadowhunter in the Institute was here for dinner and it wouldn't do if the family everyone always looked up to started arguments when they were even more scrutinised than usual. This had led to both of them settling for the occasional glare over the table.
Alec had no right to be angry. He'd started this. If it hadn't been for his stubbornness, none of this would have had to happen, but no. Of course things had to go his way; always his way, just because he could. And it wasn't like Jace expected an apology from him; Alec could probably set the Institute on fire and still wouldn't deign to say he was sorry. It was his parents's philosophy shining through and Jace wouldn't have blamed him for it if it hadn't been so frustrating.
He chanced another look in Alec's direction and met his eyes for the first time since they'd sat down. Alec responded with a dispassionate glance which made Jace's blood boil even more. His entire body itched for a fight. Not just any fight - he wanted to drag Alec down to the training rooms and give him a piece of his mind and probably a punch in the face; wanted to do anything that would manage to get a reaction out of him.
Of course, he couldn't do that without causing a scene, so he settled for a kick in Alec's general direction hoping that it would seem accidental. Alec finally looked up from his mashed potatoes (which Jace considered to be at least a small achievement) but didn't say anything. He just raised an eyebrow in something that looked suspiciously like a challenge - is that the best you can do? - before returning to poking around his plate. He'd narrowly avoided attracting Maryse's attention and Jace decided to add that to the list of things that infuriated him, both in this situation and in his parabatai in general. He was aware that it was petty to resort to childish provocation, but there was nothing else he could do that wouldn't ruin the united front the Lightwood family made in the eyes of everyone else just then. And Alec knew that; he knew that he didn't have to do anything to get the upper hand besides just sitting there as the perfect image of propriety and innocence he made.
Jace wished that someone had thought to create a universal sign for, "I'd strangle you but the Blackthorns are looking at us and then Maryse would strangle me." It would have been rather useful, and it would have probably wiped the expression of smug indifference off of Alec's face for at least a moment.
Alec looked at him from under his lashes and Jace was surprised to find that said expression had already disappeared in favour of something he couldn't quite define. It was surprising in its intensity and Jace felt tempted to just ask what was going through his head, appearances be damned, but he didn't get the chance. Alec turned to the side and said something to Maryse that made her purse her lips for a second before she nodded. Alec pushed his chair back and stood up, studiously avoiding Jace's questioning glance, making his way out of the hall as if he was being chased.
Without waiting for his cue, Jace followed his example, the anger from before extinguished just a fraction to make room for curiosity. He didn't know for certain what he'd do when he found Alec, but he was sure he'd figure something out.