Hi guys! So, I decided to write a story about what might happen if Jace cheated on Clary. I know there is already tons of those stories but I wanted to post one of my own. This story will be in a few perspectives but mostly Jace and Clary's POVs.

Clary's POV

I paused. I had been walking up to my room, which was right across from Jace's in the Institute. I'd been marveling over how my mom had finally let me move in to the Institute. She would still see me all the time, but it had still taken Luke's reasoning with her before she agreed. From Jace's room came a moan. I tensed, reaching for a seraph blade hidden in my knee-high boots that Izzy had finally convinced me to wear. What if a demon was in Jace's room? As soon as I thought it I laughed at myself. Demons couldn't come into the Institute. And the moan sounded more… pleasured.

I inched the door open and peered inside. I felt my heart leap into my throat as the ability to speak left me. Jace was in his bed, on top of another girl. She was the one moaning the first time, but they were both doing it. I stared breathlessly. They were both naked. I saw Jace's eyes open and his golden gaze pierced me. "Clary!" he gasped. The blond girl looked at me with a pleased expression. I felt my heart contract. It was Kaelie Whitewillow, the stupid fairy waitress from Taki's that always flirted with him.

I shook my head wordlessly and slammed the seraph blade that I still held in my hand into his floor. The tears finally started coming as I turned and ran across the hall into my room. He followed, coming in my room, still naked. "I can explain, Clary-" he began, but I cut him off.

"I don't want your explanations, Herondale. We are done. If we ever see each other again, I will break your arm." Shaking my head angrily, I turned and started throwing clothes into a bag. I grabbed my sketchpad and tore out a drawing of him, holding it so he could see as I tore it into pieces and crumpled it up before throwing it to the floor.

I snatched my stele from the dresser, drawing a Portal, picturing where I wanted to go. Finally, I drew a rune that came to me on my skin. Untrackable. "If you want to find me, it will be the old fashioned way." Slinging the backpack over my shoulder, I stepped through the Portal, hearing his voice call after me as I kicked the swirling vortex, destroying it before he could follow. I sighed, walking towards the Miami Institute.

As soon as I knock on the doors, they open to reveal a delicate looking girl with violet eyes and ebony hair. She is very pretty, the scars and marks from runes revealing her Shadowhunter status. "Hi, I'm Clary Fairchild and I need a place to stay." I tell her, hastily wiping away the last signs of my tears.

"Oh, no way! The Clary Fairchild? Jace Herondale's girlfriend?" she says, somehow managing to make her excited tones seem chill, like she doesn't care.

I smile weakly. "Not anymore." She frowns concernedly at my expression.

"I'm Alexa Fairfox. Welcome to the Miami Institute. Don't worry, there aren't any alligators on the streets." she cracks. A less fake smile appears on my face as I walk into my new home.

Jace's POV

I don't know why I had sex with Kaelie. I went to Taki's for lunch and she was my waitress. I think she put alcohol in my coffee, because when I was done with it, I was very energized and very drunk. "Let's go back to my place." I slurred in her ear while I paid. She smiled seductively.

"Sounds good to me." she replied, following me out of Taki's. Once we got back to the Institute, she settled herself on my bed, kissing me fiercely. One thing led to another, and the next thing I knew Clary was standing in the doorway.

I tried to get her to stay, but she wouldn't listen. I didn't blame her. She stepped through her Portal and as I throw my still naked self at it, it shatters the second before I go through, and I smash into the wall. She must have broken it from the other side. She had said that if I wanted to find her, it would have to be the old fashioned way, right after she had drawn a rune I didn't recognize on herself. Did she mean… I grabbed a stele from off her bed, concealed in her covers, and drew a tracking rune on her sketchbook. Nothing happened. "Damnit Clary!" I yell, frustrated. She must have created a new rune, probably making her untrackable.

I chuck her sketchpad at the wall where she had disappeared into a Portal and watch it bounce off. I heave myself off her bed and go back to my room, finding that Kaelie at least had the decency to get her clothes and go. I get dressed and decide not to tell the others when they got back why she had left.

Clary's POV

2 years later…

I laughed, grabbing Alexa's arm as she fought me for the last muffin. Even at so young, she was the head of the institute and we lived almost alone, with just Alexa's brother living here. Alexa and I were parabatai and she had long since known about Jace. She had then begged permission to go kill him. I had laughed, but said no. She could've, though. We had gotten the title of best Shadowhunting team by killing the most demons of anyone in the world.

"It's my muffin!" I giggled, grabbing at it. She slapped my hand away, but before she could snatch it for herself, a hand grabbed it and stuffed it into their mouth. "Brad!" I complain, laughing as I kiss him. Brad is Alexa's brother and my boyfriend. I loved that every time I kissed him, I didn't have to worry about going up on my tiptoes. I had changed a lot in the two years since I left, my hair staying wild, but a bit sleeker and smoother. When the light hits it, it is gorgeous, decorated with some blond highlights. I had filled out a lot, getting a growth spurt and more curves.

We walked to school together after the muffin incident. Alexa and I, along with Brad, were definitely popular. I usually dressed in all black, a form fitting tank with black skinny jeans and a leather jacket. We all dressed pretty badass. No one crosses us and gets away with it. I yawn through all my classes, excited to get home to train. It's definitely more exciting than math class.

Finally we made it home, and I ran upstairs to my room to change for training, easily dodging through the maze of halls that was the Institute to get to my bedroom. I pick out tight shorts and a sports bra, brushing my hair back into its ponytail and out of my face, also removing the makeup I wore during the school day. I ran back downstairs to stop short before I run into Alexa, who seemed to be walking to my room and looks very nervous.

"Um, Clary, you have visitors." she mumbles.

"Who?" I asked.

"Just, don't be your usual sarcastic self." she responds. I fake pout, nudging her shoulder with mine as I jog to the door and open it. I stop short. Right there are the people I ran from in the first place. Simon, Alec, Magnus, Isabelle and Jace stand in the doorway. "Um." is all I can say. Alexa comes up next to me, a fake smile on her face. She rubs my back where no one can see and does her best to calm me down. I take a deep breath. "Hi guys." I say weakly.

Isabelle squeals as she runs up to me and hugs me, and it's like the invisible wall of time in between the gang and I breaks. Suddenly everyone is surrounding me, hugging and offering greetings and how-have-you-beens. Everyone except Jace, who stays leaning against the doorframe. I eventually break from the group, going next to Alexa, who is standing awkwardly outside of the group hug. "Everyone, this is Alexa Fairfox. She is my parabatai and can kick all of your asses. So just, be careful with her."

"Why did you leave Clary? When are you coming back to New York? When did you get a parabatai? How are you the best Shadowhunting team ever? How are you so tall? When did you get hot?" Isabelle bombards me with questions. I do my best to answer.

"If you want to know why I left, ask Jace for an explanation. If he lies, I will tell you. I am not coming back to New York now or ever. I got Alexa when I came here. Her parents died, so she is the head of the Miami Institute here. I don't know how I am so tall or when I got hot. Puberty? And I have questions for you. How did you find me? How did you know we are the best Shadowhunters?" I question.

"I can answer that." Simon says, stepping up. "We couldn't find you anywhere and tracking runes and spells didn't work, so we went to the Clave and they told us that you and your parabatai lived here, and were the best Shadowhunters ever."

I notice that they are all carrying bags, and change the subject. "Are you guys planning on staying here?" I ask with more enthusiasm than I feel. Izzy nodded, beaming. I nod numbly and Alexa volunteers to show them to their rooms. I look at her gratefully. Thank you. "Then, um, I'm gonna go to my room. I will see you for school tomorrow." I turn and run out of there, hearing their groans from when I mentioned school as a chorus shooing me out.

Simon chases after me. Using his vampire speed, he can easily beat me to my room as I race through the twisting hallways, but since he doesn't know his way around he doesn't. "What's the matter Fray? What did Golden Boy do to make you leave?" he asks when I stop at my room. I don't want to tell him, but this is Simon. I can trust him.

"Okay." I sigh. "So, you know Kaelie Whitewillow? The waitress at Taki's?" He nods. "I might have walked into Jace's room and found them having…" my voice trails off as I begin to cry. He hugs me close, somehow his lack of body heat warming me.

"Wait, so they didn't just make out? He actually…" I nod wordlessly. He sighs, hugging me for a few more seconds before asking me how to get back to the foyer of the Institute. "I need to beat the crap out of Herondale." I laugh a little and lead him back.

"HERONDALE!" he shouts.

"Chill, bloodsucker." Jace looks faintly amused, until he looks past Simon to me. He draws in a sharp breath as I nod to his unasked question. "Shit." he mutters as Simon descends on him.

"You cheated on Clary." he asks, saying it more as a statement than a question. Isabelle drew in a sharp breath, the words having a similar effect on Magnus. But Alec jumped to his parabatai's defence.

"Seriously Simon?! Why would you assume that?!" Alec looks furious.

"I'm not assuming it Alec. Have you even looked at Clary?! Let's say I have reliable information." he hisses angrily. Alec looks at my face and I can picture what he sees. Tear tracks down my face, looking anywhere but at the gang. I glance at Alexa, and she nods encouragingly. I let out a sigh and look up at Alec as I nod.

Alec looks furious. He walks up to Jace and slaps him across the face, hard. I find courage and anger somewhere deep inside me and slap him too. "You deserve that." I hiss. "You broke my heart. For a full year I cried myself to sleep. For a full year I didn't let anyone near my heart except Alexa. If you want me back, you better try hard. I don't cry myself to sleep. I have many dear friends. Do you know, when I told Alexa she wanted to kill you for hurting me like that?" I growl, looking towards her as I speak. Her face is also contorting into rage. "Things have changed, Jace. I have a boyfriend. And I am giving Alexa permission to kill you, now that you are ready."

"Tomorrow in the training room after school. I will murder you, Herondale." she rages furiously.

"Please. No one can beat me. I'm the best Shadowhunter there is." he scoffs.

"Ah-ah, Jace. You were the best Shadowhunter. Now we are." I say patronizingly, gesturing between Alexa and I. Alexa whips out her phone and begins texting someone.

"Jace… is… here." she mutters as she hits the keys.

"Who?" I ask.

"Johnathan." she replies. I nod appreciatively.

"Johnathan who?" Izzy questions.

"Johnathan Adams." Alexa supplies, her smile widening at the reactions she gets. Everyone knows Johnathan Adams. He is a werewolf who was turned, and a week after his family was attacked by rogue vampires. He killed them all and made a big name for himself. He also knows my story and despises Jace, almost as much as the rogue vampires he killed. And now he is on his way.

Someone knocks on the Institute doors. I let him in. Johnathan is in his scariest form, mostly human with wolf claws, paws, and teeth. "Are you okay?" he asks anxiously. I nod.

"The rest of the gang pretty much hates him too. Just… don't kill him. I wouldn't want to do that to Alec and Isabelle." He nods back.

"HERONDALE!" he yells. Jace comes towards him cockily.

"Yeees?" Jace asks.

"You're dead." he growls, lunging at Jace. Jace's eyes widen as in midair, Johnathan goes full wolf. Landing perfectly, he prowls towards the motionless Jace.

CLIFFHANGER! Agh, hate those things. So what do you want me to do with Jace and Johnathan? I will be posting again tomorrow. But DON'T get used to it. I usually will be able to post once a week, on the weekends.