Major spoilers for Born to an Endless Night.

"Magnus?"

"Hmmaghr."

"Magnus."

He groaned.

"Magnus!"

Magnus shot awake, eyes just a little wild. "What?"

Alec gave him an unimpressed look. "You're on fire."

Huh. So he was.

Well, more accurately, his sleeve was on fire. He had been entertaining Max with the blue sparks he so loved, when he must have dozed off and lost focus. Sometimes the sparks could catch things on fire. Not a big deal.

He put out the fire and bounced Max on his knee.

Max was giggling.

"Do you think it's funny when Daddy catches himself on fire?"

Max giggled again.

Magnus grinned, exhausted but enraptured with the baby. Alec sat down and took Max from him, guessing what his boyfriend had in mind.

Magnus winked at Max, and fire appeared on his palms and traveled up his arms.

Max drooled and clapped his small, pudgy hands.

Magnus had a small heart attack when he woke up and couldn't find either Alec or Max right away. Alec hadn't been in bed with him, and Max hadn't been in his crib. He heard a soft noise coming from the den, so that was where he went.

He gave a small sigh of relief when he saw Alec carrying Max, walking around the room and soothing him. Max must have woken up crying, and Alec - saint that he was - must not have wanted him to wake Magnus.

Alec was sweet and thoughtful like that. Even if he wouldn't admit it.

Alec was saying something Max. Magnus strained his ears to hear. "A la claire fontaine, m'en gallant promener..." It was French. It sounded like a lullaby. "...Il y a longtemps que je t'aime. Jamais je ne t'oublierai." The words brought to mind a memory, a day spent with Alec in what seemed like another lifetime.

"I used to be scared of dark," he remembered Alec confessing once, laughing as he said it. "Ironic, right?"

Magnus shook his head. "Not really. What child isn't afraid of the dark?"

Alec shrugged. "Whenever I had nightmares, my mother would sing to me. A French ballad - A la claire fontaine."

Magnus smiled and went back to bed.

Sometimes when they were alone, Magnus spoke Indonesian to Max. He couldn't help it. It was his native language, and he wanted to share a part of himself with his son. Something personal.

One time, Alec walked in. He immediately recognized what Magnus was doing - he knew a little bit of Indonesian. He picked up languages quickly and with ease, and they had traveled to Indonesia a few times and had mostly recently vacationed in Bali.

Alec raised an eyebrow.

Magnus tried to play it off. "So he'll grow up trilingual, that's good right? Don't think I don't know that you talk to him in French, Alexander!"

Alec just chuckled. "If Jace had it his way, Max would grow up octolingual or some sh-something. Or something." They were both working to correct their profanity.

Magnus scoffed. "Tell Goldilocks that he'll stay away from my son if he knows what's good for him. Last time he babysat, he was trying to teach Max the names for different weapons."

"He means well."

Magnus went back to feeding Max. "Open," he told Max in Indonesian.

He saw Alec smile out of the corner of his eye.

They were at the Institute, in what would probably be considered the den in a normal house. Alec and Max were sitting on the floor playing. Magnus had left to get a drink and was now watching them from the doorway, unable to believe that this was his life now.

Isabelle materialized beside him. She smiled at the sight of her brother - maybe because she thought the scene was cute, maybe because seeing Alec holding a baby while he was all Marked up and in Shadowhunter gear was a little funny. (And a little adorable)

"He's a good dad," she commented. "I've always thought that he was meant to be one."

Alec had covered his eyes with his hands. His legs were crossed under him. "Where'd I go, Max?"

Max, who was a certified professional crawler and was working on adding walking to his resume, patted Alec's knee.

"You found me!" Alec exclaimed. "Look how smart you are."

Max used Alec's body to stand up. He managed a wobbly step or two before falling. He didn't cry, just giggled and drooled a bit.

Alec was beaming like the proudest father. "Look at you. Once you've mastered walking on your feet, I'll teach you how to walk on your hands," he offered.

Max tilted his head to the side.

"Like this." Alec stood up and fell into a perfect handstand. He walked around a giggling Max in a circle like that, even balancing on one hand for a few moments. He let himself fall back onto the floor, somehow managing to land silently.

Max crawled toward Alec.

Magnus smiled at nothing in particular. "Yeah, he is," he agreed.

"I used to think that Alec would never get to be a dad," she admitted, sounding almost ashamed. "Or that if he did, it would be with some Shadowhunter girl he didn't really like. It's just...I'm really glad he got the chance to do this. With you."

Magnus thought about his namesake. The Magnus effect. All about being taken somewhere you never expected to go. He had certainly never expected to be a father, and yet here he was. Magnus was more than happy with how everything had turned out.

"I am too," he told Isabelle. "More than you know."

Being a parent came so naturally to Alec, it seemed. Magnus was trying his best, but he felt like he was always one step behind his boyfriend. Not that he minded. Magnus loved a challenge, but more importantly he loved seeing how happy Alec was.

"Some vampire motorcycles can fly," Alec was telling Max, still lying on his back. Max was sitting on his stomach. "Jace used to not believe me, but I'd read it in this one book. Don't listen to Jace, Max, he's an idiot. You'll find that out for yourself eventually."

Max made a burbling noise.

"Do you want to play Vampire Bike, Max?" Alec picked Max up and lifted him into the air, narrating the entire time. "When you ride on a flying vampire bike, you go up! Then down," he said as he brought Max closer to his chest. "Then up! And down! And if you're a really awful driver like Jace, then sometimes you go side...to side...to side...then up!" It was like watching a mundane parent playing Airplane.

Max was giggling so much, Magnus was a little worried he was going to spit up.

Isabelle kissed his cheek. "I'm grateful for you, Magnus Bane." Then she announced her entrance to Alec with a flourish. "It's my turn to play with Max!"

Max was so excited to see his aunt that he actually did spit up. Right on Alec's shirt.

Alec sighed.

Magnus laughed. "Better you than me," he said, joining them on the floor. "This shirt is Armani."

It had started with Max flailing and hitting Isabelle on the nose.

They were all gathered at Magnus and Alec's apartment. Jace had wondered what was taking the two so long in the bedroom - he'd been scared to find out - but when he went to check, he'd discovered them passed out on the bed, exhausted and on top of all the covers. So they all took the opportunity to steal the couple's baby for a few hours.

Jace cheered. "Just like that, Max! The nose is very sensitive, always a good choice when you're dealing with things that have noses."

Maryse scoffed. "My grandson will not be a brawler. I'll train him myself if I have to."

Isabelle rolled her eyes. "Please. If you think that Alec's not teaching him how to throw knives and use a bow the first chance he gets, then you're crazy."

Simon scrutinized Max. "Do you think he'll be doing magic soon? Like Magnus?"

Isabelle shrugged the best she could with a baby in her arms. "I don't know. That'd be cool. It sounds like something Magnus would totally do - teach his kid how to do magic."

Jace added, "I have dibs on teaching him how to use a sword."

"That's fine," Isabelle said. "Everyone knows-"

They wouldn't get to find out what, in fact, everyone knew, because Max started crying for his parents.

"Shh, Max," Izzy said soothingly. "Your daddies are tired. Do you want to go to the kitchen? I'll show you how to make soup," she said, already strolling out of the room.

Everyone exchanged terrified looks and ran after them.

Sorry if this kinda sucked, I only recently read Born to an Endless Night and wrote this right away, so not a ton of editing went into this.

Please leave a review telling me what you think, or leave me a prompt for another one-shot.