I just started watching Shadowhunters and of course I'm obsessed now. I haven't finished the show yet, but I had to start writing anyways. This takes place post series finale time jump, but fixes everything because I love a happy ending for everyone. If I have any important details wrong, forgive me. I've only looked at spoilers for most of what happens in season 3, so some stuff might be off.

Jace quickly made his way toward Isabelle's office, eager to find out what was going on. Isabelle had sent for him and said she needed his help with Alec and Magnus, but she didn't say what was wrong. He doubted that either of them were injured, since there would've been more urgency in the message, but that didn't mean he was going to take his time to find out what the deal was.

Alec and Magnus had been married for a while now and it had been going well as far as he could tell. It wasn't like he had any experience in that regard, but he was around them enough to see that they were genuinely happy and in love. Too much sometimes if you asked him. It wasn't that it made him uncomfortable. Okay, that wasn't completely true. It wasn't that they made out all over the place. The kisses Jace could handle. It was the mushiness that made him want to run from the room screaming. It wasn't normal how often they could tell each other "I love you" in one conversation. Especially when they were talking about something completely unrelated to their relationship.

"Do you know what's going on?" Clary asked, trotting forward to catch up with him. He grabbed her hand and brought it up to his face to give it a kiss. It had been a few months since Clary's memories and abilities had come back and they picked up right where they left off.

"Not at all. Isabelle called for you too?" Jace replied.

"Yeah, she said she needed help dealing with Alec and Magnus. That they were having some sort of fight," Clary said, biting her lip in worry. That was more information than he'd gotten, but it didn't help calm his nerves.

"I'm sure everything's okay," Jace soothed, wrapping his arm around Clary as they walked the last few halls to their destination. "It's Magnus and Alec."

"Thank the Angel you guys are here," Isabelle said as soon as they opened the door. "I can't stand another second of their sniping." Jace couldn't see any blood, so that was a good sign so far. Alec was sitting at the desk with his arms crossed, looking every bit like the stiff man Jace had known most of his life. He'd relaxed considerably these past few years, but it looked like whatever was happening had thrown that progress right out the window. Magnus was across the room, carefully avoiding making eye contact with his husband.

"What's going on?" Jace asked, hoping this could be easily solved and they could go back to living their lives peacefully. He'd agreed to pose nude for one of Clary's drawings later and he wanted to have one last training session to make sure everything was as tight as possible.

"They won't tell anyone, but that hasn't stopped them from throwing barbs at each other," Isabelle sighed, glaring at both of them. "I called them here for help with a warlock issue and they were already like this when they got here."

"Do you think it's a curse?" Clary asked, scrunching her nose in contemplation.

"We are not cursed and also, we can hear you," Alec said, rolling his eyes.

"Okay, so what's the problem then?" Jace asked, moving to stand next to his parabatai. If there was something really wrong here, he was going to stand by his brother. He loved Magnus like family now, but nothing compared to his bond with Alec. Jace would choose him no matter what, especially after making the mistake of not doing so in the past.

"The problem is your brother is too stubborn to admit when he is wrong," Magnus declared, waving a dismissing hand in their direction.

"Oh, that's real rich coming from you, the man who always has to get his way," Alec scoffed.

"Can't you guys just come to a compromise?" Clary suggested, walking over and putting a hand on Magnus' arm.

"I'm afraid it's not that simple. There is no in between with this one," Magnus sighed, spinning on his heels to finally face Alec. "And what do you mean by that? I do not always get my way."

"Really? You choose what we have for dinner every night," Alec pointed out.

"Doesn't Magnus always magic up Alec's favorite foods from every corner of the world?" Clary whispered to him. That was true. They'd had dinner together just last week and Magnus had conjured Alec's ideal meal, even down to the brand of after dinner mint.

"And yet you always decide the drinks," Magnus shot back.

"Doesn't Alec always make Magnus a cocktail when he gets home?" Clary whispered again. Alec still wasn't much of a drinker, but he'd taken a mixology course to learn how to make all of the things Magnus loved to drink. Jace had been sworn to secrecy of course and had been the guinea pig for all of the test runs.

"And what about that watch you gave me? It was gorgeous," Alec snapped, standing up from his seat and pushing his chair back angrily.

"It was very easy for me to get, unlike the rare spell book you found me. That took much more effort on your part!" Magnus shouted, sliding a table out of his way with magic so he could stomp to the middle of the room unimpeded.

"And it was worth every second!" Alec yelled, stalking up to stand in front of him.

"Wait-" Clary mumbled.

"I'm sorry, I'm sorry!" Simon panted, running into the room out of breath. "This is all my fault."

"How are you out of breath? You don't even breathe," Jace scoffed.

"That's not important right now," Simon brushed off, walking over to stand with Isabelle.

"That's usually true," Jace agreed, ignoring Clary's sharp poke in his side.

"Whatever. I know what they are fighting about," Simon said, biting the inside of his cheek guiltily.

"Sweetie, what did you do?" Isabelle asked, reaching up to cup his cheek. Yet another couple who made Jace want to puke sometimes.

"Well, I was talking to Magnus on the phone before they portalled here, getting his advice on a vampire thing. The details aren't important," Simon said quickly, cutting off Jace's question. "Anyways, I said something offhand and I didn't realize Alec was listening and suddenly they were arguing and then they hung up."

"So, what was it? What did you say?" Isabelle asked.

"Yeah, what are they arguing about?" Jace prodded.

"They're-" Simon winced, flicking his eyes between the warring men. "They're fighting over who has the best husband."

"Oh my word," Isabelle groaned, pinching the bridge of her nose.

"Aww!" Clary cooed.

"Who has the better husband?" Jace asked, wanting to know where each of them stood.

"I do!" Alec and Magnus insisted simultaneously.

"Aww!" Clary cooed even louder. Jace shot her an annoyed look. They shouldn't encourage this. "Oh, come on. There is nothing wrong with being happy and in love." Jace grumbled under his breath a little, but didn't argue. The engagement ring he had tucked in his pocket made it feel wrong to.

"Come on guys. Can't you just agree that each of you has the best husband that individual could ask for?" Simon suggested.

"What do you say to that?" Magnus asked, tilting his head to the side in contemplation.

"I don't know. It feels wrong to agree with Simon," Alec muttered, reaching forward to thread his fingers with Magnus'.

"Hey!" Simon pouted. Isabelle shushed him with a kiss on the cheek. Jace and Alec liked to give Simon a hard time, but they did begrudgingly care for the vamp. Jace had even caught Alec warning Isabelle not to ruin things with him, since she'd have a hard time finding anyone better. Although Alec would probably deny that to his last breath, even while threatened with torture from an agony rune.

"But I do abhor fighting with you," Magnus moaned, letting his eyes flicker mischievously. "Although I quite enjoy making up." Alec's cheeks turned bright red and Jace groaned.

"Too much information!" Jace said, covering his ears. He didn't care if he looked childish. He was still traumatized from that time that he could just feel that Alec had lost his virginity. Thank the Angel that he didn't get that flash of knowledge every time they spent time together.

"No one asked you all to butt in," Alec scoffed, pulling Magnus closer to give him a hug.

"But we do appreciate that you care," Magnus added, reaching up to press a kiss to the underside of Alec's jaw.

"Get a room!" Jace jeered, smirking when Alec glared at him.

"You know, that's not a bad idea," Alec said, putting his arm around Magnus and leading him out of the room. Jace grinned, relieved that this turned out to be a false alarm and everything was the way it should be. He was just about to make a joke about annoying couples when Alec's voice from down the hall caught his ear. "We should take Jace's advice. Which room is his again?" Jace's eyes widened as the implication of what he heard sunk in. He spun around and raced out of the room, determined to intercept his parabatai.

"Don't you dare!"