Isabelle groaned, rolling her body across the thick mat that covered the span of the training room floor. Dazed, she allowed herself to steal a couple of minutes of thinking time as she stared up at the ceiling, her black hair fanning out against the floor like a waterfall.

"You're going to end up hurting yourself," said Simon, his body leant against the thick wooden doorway that opened into the room. His hands were folded across his chest and he wore an amused smile.

Isabelle blinked up at him. "How did you get in?"

"Alec," was all Simon said as he dipped down to sit next to her. Little sparks of electricity danced across the surface of his arm, which was resting just two inches from hers.

"I needed to let off a little steam," she confessed, looking at him through a thick curtain of her hair, "I don't quite understand what's happening with Jace at the moment."

Simon raised an eyebrow. "I think it's pretty obvious," he said, "I always knew Jace was full of fire – this just confirms my suspicions."

Isabelle smiled softly, her cheeks flushing lightly. "You know what I mean, Simon." With that, she hoisted herself into a standing position and laced her golden whip around her wrist. Thinking time had come and gone.

Still sitting down, Simon allowed himself to fully appraise her. His eyes dragged slowly down her body, head to toe. He loved it when she wore her hair down and loose around her shoulders. Large strands had plastered themselves against her sweaty forehead and neck.

She looked like a Goddess of War.

"What?" asked Isabelle, her brow wrinkling in confusion.

"Nothing," he replied, and then in a smaller voice, "You're beautiful."

Her whole figure stiffened abruptly, her hands pausing in mid-air.

Sucking in a deep breath, Simon stood in front of her with his hands clasped around her thin and dainty fingers. He squeezed briefly. "I think we should address our situation, Izzy."

Isabelle could have snorted if the situation wasn't so serious. "Are you implying that we actually have a 'situation', Simon? Because last time I heard, you'd been dating both me and Maia – and not very successfully, might I add."

Simon groaned. "That was a mistake," he said, "Not to mention the fact that she's now with Jordan." He ran a hand through his hair agitatedly, and then settled on watching her hands, which were fluttering across her hair as she braided it into a thick plait.

"So," said Isabelle, annoyance evident in her tone, "If she wasn't with him, you'd still be two-timing us?"

"No."

"This is why you can't trust Downworlders," she muttered.

Simon rolled his eyes. "I was human when you met me."

"That's even worse," she quipped, tying elastic around the end of her braid before letting it drop with a thud against the bare skin at the top of her chest. Her heartbeat was uneven, beating loudly against the confines of her ribcage as she traced Simon's face with her eyes. She felt like she needed to memorise it in case something bad happened and she wasn't allowed to see it again.

Finally, her eyes met his lips. They were set in a straight, worried line. It was an expression Isabelle had grown accustomed to seeing on Simon – especially when he was worried about Clary, his best friend and her adoptive brother's girlfriend.

"You're thinking about Clary." It wasn't a question.

"I'm thinking about us," corrected Simon. He placed a long finger under her chin and slowly lifted her face to his eyes. "Are you jealous of Clary, Izzy?"

"No," she said all too quickly, "I know there's nothing going on between you two." On a side note she added, "Jace would probably kill you if there was." She paused again, tasting her next words in her mouth. Her blue eyes flicked up to meet his and she smiled sadly. "I'm happy that Clary has you as a friend. You're special to her and you understand her in a way that Jace can't. But sometimes I feel like you focus all of your attention on her and let other people fall through the cracks."

Simon frowned. "By 'other people' you don't mean Magnus or anyone, right? Because he's never said my name properly, never mind relied on me for support."

"You know what I mean, Simon," she repeated.

"Yeah," Simon confirmed, his eyes growing softer as he looked down at the black haired beauty standing in front of him, "I know who you mean. I just thought we had already discussed this." Then, with a brief silence, he powered through. "I thought you knew how I feel about you, Isabelle. God – I thought everyone knew. I've been walking around like the happiest vampire on earth for weeks."

"You have?" She seemed puzzled.

"Yes!" he spluttered, "Clary can't stand being around me because I'm so happy all the time. I think even Jordan knows something's right for once, because whenever I walk in the room him and Maia push their heads together and start a round of whispering." He looked down at his shoes. "Of course, that could just be because you showered at my flat and then dressed in one of my shirts."

"You can't expect me to go to meet my family wearing the same clothes as the day before," said Isabelle defensively, "They'd get suspicious."

"And wearing my shirt isn't suspicious?"

"No – I don't know," she sighed, "I just figured it'd sound a lot better than the latter."

Simon smiled, brushing his finger across one of her cheeks. He stepped closer, moving his fingers to cup the back of her neck gently. The opposite hand snaked across her back, securing her body against his.

"So where does that leave us?" he questioned, searching her cobalt blue eyes with renewed curiosity. His fingers absent-mindedly played with a loose strand of her hair.

"I was hoping you'd tell me." She was breathing heavily now. Her hands had somehow found their way to his neck, where they rested loosely around the soft skin at his nape.

He grinned and pressed his lips to hers lightly, a whisper of a kiss. When he pulled away, he saw her eyes were closed and a ghost of a smile had settled across her lips. She looked beautiful, sweat and all.

"You're perfect" was all he said as he again tilted his head to kiss her. It lasted longer this time – enough to cause Isabelle's heart to speed up and all but pound against her ribcage.

She sighed contently and let happiness wash over her. Relaxing further, she became aware of the tingling sensation between their bodies. The same electricity coursed through his body to hers, and she wasn't aware that their kiss had deepened until he had to gently detach her so that she could breathe. Her chest heaved as she stared up at him.

"I love you," he said, so quietly that she had to strain to hear it.