Disclaimer: I don't own Mortal Instruments.

Summary: Sometimes, she allows herself to think of Jace as something other than her adoptive brother. JaceIsabelle, oneshot

So, I'm completely in love with this fandom. I know everyone is probably tired of this influx of oneshots, but I just can't get enough. And I just can't bring myself to start another chapter fic when I already have a few that are going unfinished. Anyway, this is just a little exercise, so I hope that y'all enjoy this fic of mine!

Idle Thoughts

It's hard, having Jace Wayland as a brother.

Isabelle sees how other girls look at him, how they can look at him without a string of regret. How they can freely feel what they want, without the awkward repercussions of the fact. He shines brighter than anything she's ever seen. Maybe it's because of the Angel's blood in his veins, maybe not. She has a conviction that the shine is all his own, his natural goodness seeping out of his pores, creating this being that she can hardly look at.

She knows that he's not really her brother, but still, she sees him that way most days. She knows that everyone else sees him like that every day, though. The Lightwoods and the lone Wayland have become synonymous with each other, almost like they are part of the same being.

Isabelle hates it.

Of course, some days she loves it. Loves the feeling of togetherness that her family brings.

Other days, she wants to be selfish.

It doesn't happen as much now as it used to, now that Jace has found Clary, but sometimes Isabelle allows herself to think of Jace as something other than her adoptive brother.

Some days, she imagines that he loves her in that way. In the romantic sense. She imagines his strong face looking at her the way he looks at the redhaired girl that had stolen his heart.

She imagines the way his calloused hands would feel on her, touching her in the most gentle way. She doesn't just think of the completely intimate acts either. She thinks of the glances, the kindness, the absolute love that he shows Clary, and she projects it onto herself in her vision.

It's messed up, she knows, but she can't bring herself to stop.

She can't bring herself to stop thinking of him in that way.

She can't bring herself to stop dwelling on the fact that he could have been hers.

Isabelle knows, of course, that this is a futile thought. One that she likes to tell herself. She likes to think that Jace could have been hers at one point, but that is just a pretty little lie.

So now, she just watches.

There is nothing to wait for. No glossy confessions of love or brilliant declarations of affection.

She watches all of this happen to Clary and feels like it should have been her.

Of course, she wouldn't force herself on Jace. That wouldn't be fair to him, wouldn't be fair to Clary. Besides, despite all of the strange things she thinks about Jace, she actually cares for him. Clary too. Behind her flippant exterior lies someone that shows concern for them. When they're happy, when they're sad, or whatever emotion they might be feeling, she feels it for them.

And to think that if she acted on those silly thoughts of hers, it would cause them pain... Isabelle prevents herself from even looking at Jace as if he were anything but the loving "brother" he is.

In fact, that's all her thoughts can be...just thoughts. Nothing more. Never changing, like Simon's immortal presence. There's nothing that can be done. That was the hand Fate provided her and this is what she is going to have to deal with until she moves on or...ceases to exist. The latter is a very depressing prospect, so she tries not to think on that option too much.

But, when she thinks of life beyond Jace, beyond loving him, she can see nothing else.

Jace Wayland is a very difficult person to have as a brother, indeed.

End.

Alrighty! This wasn't too much, but I enjoyed writing it. I don't think there's enough JaceIsabelle fics out there, so I made my own contribution. Anyway, I hope y'all enjoyed reading this because I enjoyed writing it! I'd love to hear your opinions on it!

Thanks so much for reading!