A/N: Hey guys! Since I wrote a Tessa/Will oneshot, I thought I'd try writing a Tessa/Jem oneshot, since I'm currently undecided if I like Will or Jem more . . . They're just so awesome! It's hard to pick. Whatever. I hope you all like this, because I really enjoyed writing it :)

Disclaimer: The Infernal Devices and its characters all belong to the talented redhead, Cassandra Clare. I wish they were mine, but they aren't. :(

P.S. If you want info on updates, follow me on Twitter! My username is iloveDimitri081 :)

P.P.S. If you like the Vampire Academy series, check out my stories! I have plenty :D The one that I'm focused on is called Together Forever, so check it out! I promise that you won't be disappointed.

Enjoy!

It was a dull day outside. Tessa sat in the library, reading A Tale Of Two Cities for what had to be at least the twentieth time. She could—would never tire of the book. She found herself getting lost in the story, so she received quite the scare when a low voice broke through her reverie.

"Good afternoon, Tessa." It was Jem, having come silently into the library, Church trailing behind him.

The cat meowed loudly before stalking off toward a bookshelf and laying at its base. Jem chuckled. "Quite the cat, isn't he?" he asked in an affectionate voice.

Tessa laughed. "He sure is."

Jem peered down at the book she clutched. "Well, I was going to ask you if you wanted to join me for a walk through Hyde Park, but I can see that you are busy. Perhaps another time."

"No!" Tessa protested. "I mean, I'm not busy. God knows how many times I've read this book," she said, brushing a curl from her face with her finger.

Jem grinned. "Well, that changes things. Tessa, would you like to take a walk through Hyde Park with me?" he asked.

"Jem, I would love to," she replied, smiling.

Jem extended his hand to her, which she accepted. Setting the book aside, she walked alongside Jem, still holding his hand, through the corridors of the Institute until they reached the doors. He pulled the doors open, motioning for Tessa to go first. Grinning, she nodded her head and stepped through into the depressing-looking outside.

She heard the doors shut behind her, then felt Jem's hand on her elbow.

They walked at a leisurely pace to the park, chatting about unimportant things such as the weather. Jem didn't speak of Will, for which Tessa was grateful. She and Will hadn't spoken at all since the episode on the roof of the Institute.

Once they reached the park, they took a seat on a nearby bench to rest for a few moments. The boots that Tessa wore weren't exactly the best choice for a stroll through the park, but she hadn't thought to change them.

"The sky is so dreary," Tessa commented. "If this had been New York, the sun would be shining."

Jem stared up at the grey sky overhead. "After living in London for years, you tend to get used to it. I'm sure that you will, after some time here," he replied, turning his gaze from the sky to Tessa's face. He smiled.

Tessa smiled in return. "I rather hope that I do."

Jem inhaled deeply. "Now, shall we continue our walk?" he asked.

"Of course," replied Tessa.

Jem stood, extending his hand once more to aid Tessa. She accepted his hand, and the two continued their walk through the park.

As they walked, they passed many other people. In the distance, Tessa could hear the delighted cries of children playing. Her heart ached as she wished for the innocence of childhood, when everything seemed simple. Simple questions with simple answers. Not like the things she'd done since arriving in London. None of that had been simple.

Jem's voice brought her from her musings. "How have you been lately?" His tone was questioning, but not prying. He was just genuinely curious.

Tessa sighed. "To tell you the truth, I've been less than happy."

"Because of Will?"

Tessa looked over at Jem, who was staring straight ahead. "You're not wrong there, Jem."

Jem stopped her, laying a hand comfortingly on her arm. "Will should not have done what he did. It was wrong of him."

"It's in the past now, Jem. I suppose that I must try to leave him be. He clearly wants nothing more to do with me," Tessa said quietly.

Jem reached up to caress her cheek, which felt wet. She hadn't even realized that she'd begun to cry. She instantly felt silly for crying in front of Jem, and she hastily wiped the tears away.

"You must think I'm silly for crying," she said, chuckling without humor.

Jem caught her hand which was still wiping away the wetness on her cheeks. "I could never think you silly for crying Tessa. It's normal," he said softly.

"Jem, I'm far from normal. We all know that," she replied bitterly. She longed to be a normal girl, not this freak of a somewhat-warlock that she was.

He rested a hand on her cheek. "Tessa, you are one of the most normal people I know. You must stop thinking of yourself as some sort of outsider, because you are just like I am on the inside."

Tessa repressed the urge to scoff at him. Despite that, his words made her feel better. "Jem, you're too kind. It baffles me that someone as nice as you could be friends with someone as horrid as Will," she told him honestly.

Jem smiled halfheartedly. "Thank you Tessa. Despite what you think, Will really isn't all that horrid. He can be quite kind, when he wants to be. I'm sure you know that."

Tessa didn't want to admit that he was right. She had seen proof of Will's kindness, though the times had been few and far between. "I suppose you're right," she admitted grudgingly. "But I don't think that there will be anything further between Will and I." Speaking the words made it seem more final. Tears sprang to Tessa's eyes again, and she focused on Jem's jade necklace to keep herself from crying. After a few moments of staring at it, she calmed down.

Jem tilted her chin up. "Are you alright? I notice that you stare at something very hard when you're trying not to cry . . ."

Tessa nodded slowly. Jem had such a soothing presence; she felt better when he was around. She cleared her throat. "I'm quite alright. It's just . . . hard. If it weren't for you, Jem . . . well, I don't know what I'd do," she said, her cheeks burning with embarrassment. She looked down at her feet.

"Tessa," Jem whispered softly, causing her to look up. "Do not be embarrassed to speak your mind to me. I enjoy hearing your thoughts, especially when they are so similar to mine." Jem paused for a moment, looking her straight in the eyes. "Tessa . . . when we first met, I instantly knew that you would become a great friend to me. But now . . . my feelings have extended beyond the mere feelings of friendship. I admire you greatly."

Tessa sucked in a startled breath. She hadn't known, hadn't thought of him in that way . . . until now.

Warmth bubbled up through her chest, chasing away the icy despair over Will. She reached out to twine her fingers through his. "As I admire you, James. I hadn't really assessed my feelings for you until this moment, but now that I have . . . I can see it all."

Jem broke into a huge smile, holding her hand more tightly in his. "Oh Tessa . . . thank you. You have just made me so happy."

Tessa smiled at him, enjoying his happiness. She realized that she wanted to make him happy, just to get a smile from him.

Jem gazed down at her, a look of uncertainty on his face. Tessa knew what he wanted; she wanted it as well. She nodded slowly to him, letting him know that it was okay.

He leaned down almost hesitantly, unsure of his actions. His lips brushed hers lightly, and she leaned in slightly further, encouraging him. His arms went around her waist in a comforting embrace as he kissed her slightly harder than before. Tessa liked the feeling; she felt safe, comforted and most of all, loved.

When they separated, Jem's eyes shone. "Shall we return to the Institute?" he asked, slightly breathless.

"I'd like that," she replied, smiling. Keeping their fingers entwined, they walked slowly back to the Institute, enjoying the time together.

~ID~

Jem found the sudden turn of events hard to believe.

In the spur of the moment, he'd admitted him feelings to Tessa. He'd been embarrassed, having made a fool of himself. He'd expected her to laugh it off or let him down gently, being the kind, gentle person that she was.

He hadn't expected her to reciprocate those feelings.

He knew he could fix her, mend what Will had done. From now on, he thought, it shall be my goal to make Tessa smile, no matter the cost. Though Will was practically his brother, he wouldn't condone any cruel behavior towards Tessa. But, that didn't mean that he would choose Tessa over Will. He'd have to balance them out.

Once back at the Institute, they split to freshen up for dinner. He watched her walk away, feeling lighter.

They sat together at dinner, but didn't speak. The dinnertable was quiet, for once.

After dinner, they split off once more. "I think I'll go finish that book," Tessa had said, turning to go to the library.

"Once you are finished, perhaps you would like to come to my room? I could play the violin for you," he'd suggested, hoping she would say yes.

"Of course! I'd love to hear you play again."

With that, they split off.

~ID~

Tessa felt as if she could fly as she made her way to the library. She was happier than she had been in days, and it was all because of Jem. He gave her hope that Will hadn't completely destroyed her.

When she pulled open the doors to the library and walked in, she immediately stopped in her tracks.

Will sat in the window seat, staring at the door, as if he'd been waiting for her.

"So, Tess. You and Jem, eh? How sweet." Sarcasm dripped from his words and he smirked at her.

"I don't see how it's any of your business. Why should you care?" she asked, slightly annoyed.

Will shrugged. "I'm simply curious, that's all."

"Haven't you ever heard that curiosity killed the cat?"

He scoffed. "That's silly talk. Am I not allowed to be curious, Tess?" he asked, raising an eyebrow.

Tess. He was still the only one who ever called her that. "Of course you're allowed to be curious, William, but I'm just having trouble seeing how this concerns you in any way."

His gaze turned cold. "This concerns me in every way," he said coldly.

"Care to enlighten me?"

Will stood up and strode over to where Tessa was frozen by the door. One arm went around her waist, the other gripped her hair. He pulled her to him and crushed his lips fiercely to hers.

Tessa was shocked. She couldn't move, couldn't do anything. All she felt, smelled or heard was Will Herondale. He didn't hold her gently, but he knew that she could take it. It made her feel good, like she wasn't some fragile little doll. He smelled like soap, warm and clean. She heard his heavy breathing and quickly beating heart that matched hers.

He shook her, trying to unfreeze her and get some kind of reaction.

Her body took over, pressing herself against him and tangling her fingers in his soft hair. Her lips moved in time with his, and it felt so natural, so right.

Jem, Jem, Jem, Jem, her mind chanted, but she couldn't find the will to end this moment. She knew how wrong this was, but she couldn't help it! She'd wanted this for so long . . .

After a few moments, her conscience won out over her desire. She pulled away hastily, Will's flushed face the first thing she saw. He was breathing heavily, almost panting even. Her breathing was much the same.

Suddenly, she was angry with Will for doing that. She was with Jem now; she didn't need the reminder of Will, or the temptation of doing it again.

Her hand went up and connected with his cheek in a vicious slap. He looked surprised; his hand went up to cover the blossoming red mark. "That actually hurt!" he exclaimed in surprise.

Tessa was not amused. "Don't ever kiss me like that without my permission again," she said venomously, glaring at him.

"Then don't kiss me back!" he retorted.

Tessa opened her mouth to say something, but no words came out. He was right; she should not have kissed him back. But she hadn't been able to help it! It was no secret what she felt about him, and he was using that against her.

He smirked. "That's what I thought."

Tessa exploded. "You knew very well that I would kiss you back! You know how I feel about you, and you just don't care. You're an unfeeling twit that only cares about himself. Why must you torment me like this? What did I ever do to you? I don't deserve this. Jem doesn't deserve this." Will winced when she brought up Jem, but didn't say anything as she continued her tirade. "Honestly, what is wrong with you? Are you so miserable that you feel the need to pass that misery on to someone else?"

"Yes," he whispered, almost inaudibly.

Tessa instantly felt bad, but she turned on her heel. "Well I'm sorry, but that's not the way to go about things. Talk to me once you've grown up, William." With that, she left the library, her destination: Jem's room.

~ID~

Jem had been walking by the library when he saw it. More accurately, he saw them.

Will and Tessa stood by the door, wrapped in eachother's arms. Jem felt as if he'd been stabbed through the heart as he saw them kiss.

He knew that it had been too good to be true earlier. She was still too hooked on Will to be able to be in a relationship with him. He'd been blinded by sheer happiness; ultimately, it agonized him.

They look right together, he thought sadly. It was true; the two fit together perfectly, complementing eachother.

Jem retreated down the hallway and back to his room, unable to watch them any longer. He couldn't take it.

~ID~

Tessa knocked on Jem's door. "Come in," he replied faintly.

She opened the door to find Jem lying on his bed, staring at the ceiling. How would she ever explain to him what just happened?

"Jem—" she began, but he held up a hand to stop her.

"You needn't explain. I saw."

He saw? she thought. That's much worse than having to tell him!

"Jem—" she tried, but he cut her off again.

"I understand," he said softly. "You and Will have something special. I won't stand in the way of it."

"No, Jem, you don't understand!" she exclaimed.

"What do you mean?" he asked, his head snapping up to look at her.

"Will kissed me. I hadn't wanted him to, believe me. But I don't know what happened! When I broke away from him, I slapped him and told him to never kiss me without my permission. We argued, and now I feel bad because I was mean to him, but Will and I aren't together. You and I are, and I'd like to keep it that way."

Slowly, a smile spread across Jem's face. He sprang up off the bed and hugged her before leaning down to capture her lips with his.

In that moment, Tessa knew that everything would be okay. Jem would make her happy, just as he always had. Though things with Will were still unresolved, she was optimistic that they would be soon enough.

How did I do? Was it better than my Tessa/Will oneshot? I kinda think it is :P

Okay, so I have a theory about the Herondales:

You know how in The Mortal Instruments, Amatis explains to Jace about how all of the Herondale descendants have the star on their shoulder because one of the ancestors came in contact with an angel? Well, I think that the ancestor that came in contact with an angel is Will! It makes sense, because in Clockwork Angel, there's no mention of him having the star on his shoulder, which means that it hasn't happened yet.

Don't ask me how I thought of that, because I really don't know XD I was just kinda thinking about it one day, and it popped into my head and now I can't shake the feeling that I'm right? What do you guys think?

Anyways, review and tell me what you thought of the oneshot and the theory. I love hearing what you guys think!

Until next time! Toodles! XD