Must her eyes be so blue? Must her skin be so purple, the ridges of her scalp so perfect and even? Must she cant her head, twist her lips, cross her legs just so?
It's distracting, and Nyreen doesn't know what to do with 'distracting'.
At first, she tries to ignore it, the way she feels when this fierce, beautiful creature moves past her line of sight, the way her mandibles seem to move out of her control and parts of her thought long dead spring to needy, insistent life. Aria is gorgeous, is powerful and demanding and so purely, utterly herself that Nyreen must pause sometimes, uncomfortably caught between envy and desire.
Next, she tries to justify it. Asari are just like that, or she was surrounded by staid, dutiful turians for so long that she's craving something completely different, or Aria has just somehow bewitched her. The last is mostly a bitter joke with herself, but from time to time she has to pause and wonder about it. Aria is so wildly, impossibly different from anything she's ever known that there must be something making her feel this way.
Eventually, she comes to accept it, to accept Aria for who and what she is. There's nothing else to be done, after all. The asari will not change, will not (cannot) be more or less than exactly as she is: the queen of Omega, the top varren of the vicious, bloody, backstabbing pile that occupies the Terminus Systems.
In some ways it's a relief when Aria makes the first move, although in typical Aria fashion that move is directly into bed and is accompanied by a sharp reminder that this changes their working relationship not at all. Regardless, it saves Nyreen the worries of attempting to approach the asari herself.
Theirs is an odd courtship, if it can be called that, where Aria shows her lover the secrets of Omega (a complex analogy, Nyreen thinks, for secrets the asari cannot reveal about herself), and Nyreen does as she's asked and tries always to remember that Aria is a person, not a space station.
But as all things must, they eventually fall apart. In a moment of clarity, Nyreen remembers herself, the do-gooder idealist trying to make the galaxy a better place, and finds that this is not where she is meant to be, not what she is meant to do. She cares for Aria with all the caring in her, but the asari is not the only one who must be who she is, and so Nyreen does as she must.
It breaks her heart, but she leaves.