Repeating the warning for incest in case you missed it or didn't get the message. Don't like, don't read. It's not hard. Also, first part is all dialogue then it goes all internalised, not sure if there's a warning for weird structure but I thought I should let you know. Not certain if the rating's right- there isn't a T+ and I don't think it's M, but everyone has different opinions so tell me if the rating's wrong and I'll change it. Enjoy!

'Where've you been?'

'With Cecily. I really like her.'

'Of course you like her. She's new and interesting and the first person to give you any real attention in months. You're permitted to like her, it gives you no excuse to be late for weapons practise!'

'Permitted?'

'Expected, then. It's only expected that you like her, but by the Angel, Gabriel, you're behaving as though you've never seen a girl before.'

'Oh I've seen girls, plenty of girls, more than you know... what's that look for?... anyway, what I was saying is I have never met a girl like her. I've never met anyone like her. I think I might be in love with her.'

'You're not.'

'Yes, I am. I think I'd know if I was in love. I'm going to marry her one day.'

'You can't!'

'What do you mean I can't? You can't just decide that you can instruct me however you please now that father isn't here. You may have missed it, but I've grown up. I'm not as young as I used to be and you can't make my decisions.'

'But she doesn't deserve you. She isn't even a real shadowhunter! Look at me, Gabriel, are you even listening? You cannot marry a girl like that!'

'You're one to talk about that! She's not even a shadowhunter? People talk you know. You think I haven't heard about Sophie and the scones. You think I don't know about your feelings for her. At least Cecily has shadowhunter blood, she just wasn't raised as one. That, at least, is something we can fix.'

'Don't say a word about Sophie. You don't understand. She's had such a horrible past and she's always pushed to the side. In her heart, she is a shadowhunter and that is what counts. She pined after Jem for so long and he never looked twice at her. She deserves to feel loved. Not Cecily. She doesn't deserve you at all!'

'Then who does deserve me, since you seem to know?... Gideon, I asked you a question. Who does deserve me?'

...

'I do'

'Sorry, I didn't hear that, you said it really quietly. What did you say?'

'I said 'I do'.'

...

'Oh.'

'Yes'

'So that's what this is about. You think that if I marry Cecily I won't have time for you any more? Gideon, you know that isn't true! I'll always have time for you and I'll never forget how important it was that you were there for me, especially when I came to live at The Institute. I know I was late to practice today and it won't happen again, but that has nothing to do with you. You of all people must understand that Cecily can't replace you, because the way I feel about her is different to the way I feel about you. You're my brother! That won't cease to matter.'

'That's not what I meant...'

'Then what did you mean?'

'I've said too much. If you don't understand, I suppose that's for the best. You weren't really listening. You never hear a word I say.'

'Of course I was listening. Don't talk like that. Don't say 'It's for the best you don't understand' like I'm a child who has stumbled across a conversation between adults that he is not old enough to hear. I can't be left in the dark. Gideon, stop looking at me like that, its scaring me. Just tell me what you meant. You have to stop thinking of me as though I'm twelve years old.'

'I don't.'

'Yes you do. In your eyes I am just a child!'

'You're not. Believe me, you're not. If I thought of you as a child, things might be a whole lot easier. If that were the case, I wouldn't feel the way I feel. I wouldn't want the things I want. How I see you is far worse.'

'And how do you see me?'

...

'Gideon, what did you mean? How do you see me. You said 'the things I want'. What is it that you want?'

'You.'

Everything was still for a moment. The boys looked at each other, neither breaking the silence, neither daring to move. Each breath was amplified in the thick air between them, as though each carried on it the plethora of thoughts in their busy, whirling mind.

Gideon wished that he could take it back. He hoped that Gabriel by some miracle would not understand. He hoped that if he did understand he would pretend that he didn't. He wanted to drop it- wished he'd never said a word. Curse his jealousy. His little brother was in love. He should be happy, teasing and congratulating him. If not, he should at least feel the brotherly need to protect, to help him find a girl better suited to him. He shouldn't watch his brother looking into Cecily's eyes and wish that he would look at him that way. He shouldn't hear 'marriage' and think of what comes after, storing up all of his jealousy for their wedding night. Gabriel was his brother. Not just a man, although that was bad enough, and a fair bit younger than himself, but also his brother. His flesh and blood. He felt as bad as when he first learned of his father and the demons. This was the same, worse even, and he wasn't merely guilty by association. But there was nothing he could do. There was Gabriel, standing before him with his still-boylike features. He gear concealed hidden muscle on his lean form and his startling green eyes watched him in awe. This boy might have been an incarnation of the Angel himself, Gideon would have believed it in an instant. And how he wanted to touch, to taste, to close the gap between them. How he wished this were someone else's child and not his parents'. How he wished he could feel this way about Sophie, who he loved as a sister or a close friend. He wanted so much to make Sophie happy, couldn't bare to break her heart, would do anything for her. He would marry her one day, he was sure of it, but he would never feel about her the way he felt about his amazing brother. He loved her equally, but would never desire her...

Gabriel was shocked. 'You'. His brother wanted him. He had said that he deserved him, was the only one that did. He didn't want him to marry Cecily, couldn't bear to hear him say that he loved her. He had asked him 'how do you see me', but in truth he felt he already knew, from the second his brother said 'feel the way I feel'. Since the start of their dispute Gideon had been watching him with these intense, ravenous eyes. It seemed as though he was unaware of it, subconsciously baring his soul. Gabriel didn't like the way it made him feel. His skin was crawling underneath his gear everywhere that was touched by his brother's gaze. His heartbeat was still speeding up, his breathing growing ragged. He should be scared by this, or disgusted. His instant reaction should not have been agreement, yet when Gideon said 'you' he had had to consciously stop himself from nodding his head. Yes, that's right, you want me. I can see it in your eyes. Good. I want you too. Gabriel had stood frozen with that thought and stared at his brother, who looked horrified at the confession that had just left his mouth. He should want to move rapidly away, not towards him. He did like Cecily. He really did. Maybe he didn't quite love her. He wasn't sure. He had nothing to compare it to. Nothing except what he felt for Gideon, but he'd tried not to think of that as love- not that sort of love anyway. Honestly, he'd tried not to think about it too much at all. He'd been quite successful at brushing it aside, except for the occasional dreams that he claimed to have no control over, but now everything was out in the open. There was nowhere to hide that wouldn't hurt his brother, and he couldn't hurt his brother. His feet were already moving.

Gideon's last shred of restraint fell away as he saw his brother walking towards him. Maybe he meant to hit him, but he didn't allow himself the chance to find out. There was no backing down now, he had said what he wanted. This was his last chance. His relationship with his brother was broken, he couldn't brake it further. He had to try, to know what it felt like for just a second so he could play it back to himself when he was missing Gabriel and musing over the stupidity of that confession. In seconds he closed the gap, placing one hand on Gabriel's waste and the other on the back of his neck, pulling his face towards his own, connecting their lips, waiting to be pushed away...

Gabriel felt Gideon's lips touch his own and everything that he had forced to the back of his mind came flooding to the forefront. He wanted his brother more than anything in the world right now and it certainly didn't feel as wrong as it ought to. Cecily's dark hair and blue eyes and overpowering confidence- those meant nothing to him right now. Only the feel of his brothers hands on his gear and against the skin on the back of his neck. The feel of though wonderfully masculine lips against his own, moving hesitantly, as though waiting for an adverse response. Gabriel allowed himself to shut off his mind for a moment, ignore any nagging concerns and focus on how it felt. How much he loved it. He threw himself into it.

Suddenly Gabriel's lips were responding to Gideon's, moving frantically to deepen the kiss. Gabriel slid both arms around Gideon's waist, allowing his hands to explore the muscles on his brother's back. Gideon gasped at the response, the acceptance, and Gabriel used this as an opportunity to slip his tongue into his brother's mouth.

It was a battle of tongues and teeth and lips and hands. Neither boy could bring themselves to pull away, glad that they had already administered runes for training that allowed then to last a little longer without breath. Neither could keep their hands still. Gabriel's had moved to the front of Gideon's gear, exploring his chest, pressing against the thick fabric and imagining the skin beneath. A moment later Gideon's hands were running along Gabriel's shoulder blades, his spine, his lower back. His hands slipped to cup his brother's backside and the other boy gasped against his lips. Gideon smirked into the kiss. Told you don't think of you as a child he thought.

Runes or not, all people have to breath at some point, and so they reluctantly drew apart, only a fraction, gasping for air. They rested their foreheads against each others' and grinned as they caught their breath.

'This changes things' muttered Gabriel.

Gideon drew back a little to look at his brother. Gabriel turned his head a little and went in to kiss him again. Their lips had barely grazed each other, the lightest touch, when a knock at the door had then flying apart, trying to straighten their messy hair and even out their breathing. A moment later and the door swung open. Sophie's face peaked round the doorway.

'You're needed downstairs for dinner.' She stated, glancing once more at Gideon with a smile tugging at her lips before she left.

She closed the door behind her and the brothers changed out of their gear, ready to head down for dinner. Gabriel reached for the door, but Gideon pressed a hand against it to stop him.

'Yes,' he said, quickly leaning in to kiss his brother, 'This changes things.'

The boys barely looked at anyone but each other all through the meal.

Hope you liked it. If anyone else wants to write this pairing let me know because I'd love to read your stuff. Also, if anyone wants to make a book cover for this then please do! Review please all :D