Many of you wanted this.
"Magnus?" Alec called as he stepped into Magnus' apartment. There was no answer. It was late, so Alec headed straight for the bedroom. The shower in the en suite was running. Ah, that's why he didn't answer, Alec realized. With a smile, Alec stripped down to his boxers and climbed into bed. His mission left him and his clothes covered in ichor, so he showered at the institute before leaving for Magnus'.
Soon, Magnus came out of the bathroom with just a towel wrapped around his waist. "Hey, I'm guessing you're staying for the night?" Magnus casually said as he pulled a pair of boxers and a t-shirt from his drawers. He let the towel drop to the floor as he got dressed.
"Um, yeah, I planned on it," Alec answered, his cheeks growing red.
Magnus picked the towel up from the floor and tossed it into the bathroom before getting into bed with Alec. Immediately, the shadowhunter's arms wrapped around Magnus. It felt comfortable and natural for them. Alec kissed Magnus' damp hair.
"Uh, so I don't want to push anything, but when do you plan to tell Maryse about moving in together?" Magnus asked as he played with the dark red bed sheet and black comforter.
"Well, I was thinking, maybe you could come to the institute tomorrow morning, and we'd tell her together?"
Magnus smiled at Alec, "Yeah, let's do it."
"Whatever she says, I want to move in with you, so I'm going to." He pecked Magnus' lips before saying goodnight and falling asleep with Magnus in his arms.
******
The next morning, Alec was woken up by Magnus rolling on top of him and kissing him.
"Good morning," Alec said with a giggle. He smiled up at Magnus. "Ready to go tell my mom about us moving in together?" He moved a piece of hair out of Magnus' eyes.
"I'll be ready in a few minutes."
When Magnus got up, Alec checked his phone. He had a text from Maryse.
Alec, where are you?
Magnus'. Be home in a few.
Alec sent the message and got out of bed. Magnus snapped his fingers to make the bed as Alec went to the closet and grabbed a sweater and pair of jeans he'd left.
Once he and Magnus were both ready, Magnus opened a portal to the institute.
"How are you feeling?" Magnus asked Alec as they stepped out of the portal.
"I'm freaking out a little, but I want this."
Magnus interlaced his and Alec's fingers. They walked together to Maryse's office. Alec walked in and left Magnus standing outside of the room.
"Hey, Mom, I'm back."
"Alec, did you spend the entire night with that warlock?"
"Mom, he has a name you know."
"Fine. Did you spend the entire night with Magnus Bane?"
"Yes, I did, Mother. He is my boyfriend, and I need to make time for him."
"I understand that, but you don't need to spend an entire night with him."
"What are you so worried about, we didn't even do anything."
"I don't want you to spend anymore nights at his house."
At that moment, Alec looked toward Magnus, signalling for him to come in. Alec held out his hand, which Magnus held tightly.
"Well, Mom, we came to tell you that Magnus and I have decided that I move in with him."
Maryse was silent. Her jaw was tightly set. Alec could tell she was pissed.
"And why have you decided this?" She asked, gritting her teeth.
"I am in love with Magnus," Alec said confidently.
"Alec, you're next in line to be the head of the institute, you need to do your shadowhunter duty."
"I know, but Magnus... he's my world. I want him to be there, right beside me, when I am the head of the institute."
"Alec. I don't think—"
Alec cut Maryse off, "No, Mom. I am an adult, so I am making this decision."
With that, Alec and Magnus turned and walked out of the office, leaving Maryse in a shocked silence.
"Let's go to my room," Alec said as he guided Magnus through the institute.
"I can't believe I just did that," Alec said when he and Magnus were inside his room.
"Did you really mean that?" Magnus asked.
"Mean what?"
"That you want me next to you when you become head of the institute."
Alec slid his hand down Magnus' arm and squeezed his hand.
"Of course I meant it. I meant every word I said to her."
"Alexander, I'm proud of you. You stuck to what your heart told you."
Alec pulled Magnus into a hug.
"I love you," Alec whispered.
"I will always love you," Magnus whispered back, making Alec giggle.
