Malec Oneshots- fluff, romance

Training

The Institute doors opened in front of Magnus. Isabelle hurried out, ponytail swishing. She was wearing a blue tank top and grey jeans with a purple leather jacket. Her stilettos clicked on the steps.
"Hi, Magnus!" she said pleasantly, stopping to kiss him on both cheeks. "Here to see Alec?" She winked.
"Yes. Where can I find him?"
"Training," she called over her shoulder as she wandered down the sidewalk.
Magnus smiled and walked inside. Izzy was an angel. He was pretty sure she knew about him and Alec and approved. It was only the matter of making Alec realise what they had together. What he could never have with a woman.
Clary gave him a curious look- but didn't greet him- when she watched him enter the training room. She was standing with Jace and Lydia and they were determinedly examining the projection of New York City. He got the feeling Clary disliked Lydia because she had the strangest expression on her face.
Alec didn't notice him come in. He was beating a punching bag, the sound of it echoing through the room. His hair was disheveled and hung over his forehead, which was beaded with sweat. He was wearing his sweatpants and combat boots but no shirt- and Magnus' eyes flickered over the muscles straining in his back, underneath his runes. You couldn't have paid him to look away.
Alec gave the bag one resounding clobber before raking his hand through his hair. He turned and startled, seeing Magnus there.
"Magnus," he said and immediately blushed. "What are you doing here?"
Magnus shrugged and smiled warmly. "I wanted to see you."
Alec opened his mouth to say something. Then he closed it. He didn't know what to say. He slowly walked towards Magnus, his hands clinging to his waistband. Willing himself to be calm.
"Magnus, I wish I knew- I-"
Magnus placed his finger against Alec's lips. Alec froze.
"I understand."
Alec smiled and Magnus lifted his finger, brushing it across Alec's cheek. It lit a spark inside Alec. He pulled the warlock closer to him until their lips were a whisper away. Magnus waited. He needed Alec to make the first move. Alec brushed a pink-tipped strand of hair away from Magnus' face and closed his eyes. Their lips met and it was better than either could have imagined. Despite his zero experience, Alec's mouth fit perfectly inside Magnus'. His kisses were rough and passionate and sweet all at the same and it was all Magnus could do not to to take him then and there. He placed his hands against the Shadowhunter's scarred chest and felt the muscles there. Alec moaned in his mouth, the sound captured by their kiss and it was so much all at once.
He pushed Magnus away, shaking. He needed to go and think. That's what he needed to do.
"I have to go," Alec said too loudly.
Magnus sighed. His eyes were full of hurt but he smiled. "Can I at least get your number?"
Alec heard it distantly as he slipped out of the room, clicking the door shut behind him. His boots thudded on the wooden corridor floor. If he could just get to his bedroom and rest, when he woke up, he'd know what to do. He wouldn't feel this desperate, aching longing for Magnus' touch. Alec wished he could just be with Magnus but no matter how hard he tried, he couldn't forget the look of disappointment he would see from his parents or having to prove himself to the Clave again. First born son of the Lightwoods- heavy is the head that wears the crown.
Magnus meant something to him yet so did his reputation and his precarious feeling of belonging. He couldn't let even a crush separate him from that.
A crush. He'd never thought of Magnus like this, never allowed himself to. Once he met Magnus, his obsession with Jace ended. This is what it's supposed to be like, Alec remembered thinking before running away like he always did. And that's how he had felt ever since: he could almost trick himself that they were together, an infinity. But they weren't.
Alec pushed open his bedroom door. His clothes were scattered all over the floor and his closet door was slightly ajar. Not bothering to change out of his pants (just kicking his boots off) he crawled under the covers. Sleep snatched at him and he fell into darkness.