Secrets
It was an awkward thing sometimes, to be in a secret relationship on the ship. Secret, if only because of the political scandal that would ensue back in the Plants if anyone ever discovered this relationship. "No way, Athrun Zala and Nicol Amarfi?!" they would say, "Two sons of councilmen?"
That's not even getting into what would obviously be the worst of it, "But isn't Athrun engaged to that Lacus Clyne? What about that arrangement, then? It's such a horrible political scandal!"
And so, it remained a secret between the two of them. Nicol was especially careful of keeping it hidden from the world. He was worried not for his sake, but instead, Athrun's. Athrun was careful about it as well, but never seemed to realize the impact it would have on him if news of their relationship ever got out.
They had to proceed carefully with their relationship. It had started innocently enough. They had gotten to talking in Athrun's room one time. Athrun was preparing to take a shower as they talked, and he had quickly noticed Nicol's blush and hurry to turn away from his friend as Athrun began removing clothes. It was an awkward conversation than ensued, but one that ended pleasantly enough, with a quick kiss on the lips. Nicol, flushed and embarrassed, hurried out of the room, trying to avoid Athrun for a while.
Avoiding him didn't work. When you're on the same little ship for months at a time, in the same small squadron no less, it was impossible to avoid him. In retrospect, Nicol knew it was a foolish idea, an emotional one, but he didn't regret it. After all, it gave them both some time, at least, to think about their relationship. So Nicol managed to get about 24 decent hours away from Athrun, giving them time to think.
And when they finally did confront each other, they had come to two different results. Athrun pulled Nicol aside shortly before a meeting about what do to about the Archangel, and they talked. Athrun had come to the conclusion he wanted to try this out. Nicol, on the other hand argued that it would just be too hard to pull off. He cared too much to let something bad to happen like he knew it would. But Athrun, always a good debater, convinced him otherwise. Nicol didn't put up that strong an argument in the first place, he wanted to be convinced. Logic be damned.
It started innocently and cautiously enough. Mostly it just consisted of spending more time together in each other's rooms. No one suspected anything, of course not. Athrun and Nicol were close enough friends, after all, there was no more reason to consider them a couple than to consider Yzak and Dearka one. So they had that to their advantage, but they still had to be careful. They both took to it quickly enough.
But they both started to grow relaxed. They started doing little things in public – touching each other a bit more, whispering in each other's ear. It was Nicol who first noticed this problem. He knew he might be being a bit of a "worry wart" as Yzak liked to called him, but he figured he would rather be too safe than be found out. Athrun, on the other hand, was more laid back when it came to noticing this, but when Nicol did point it out and argued about how dangerous it was, Athrun did agree. So they made sure not to do it in public any more.
It was enough to get them paranoid, though. Every little glance, every little comment started to make them a bit nervous. They just smiled and laughed it off, somewhat awkwardly, and changed the topic as quickly as possible.
It was even more awkward when they got shore leave together. Of course they missed their family and friends, but it was also a nice chance to be together, away from life on the ship. But it was difficult to do that among so many other things going on, especially with families in high political places. And of course, for Athrun, he had Lacus Clyne. While he did not feel in love with her romantically, he definitely did like her as a friend, and naturally, he was engaged to her, so he had to spend much of his time with her as well. If only to keep up appearences. Nicol felt a bit jealous, but he was so busy himself that he couldn't really complain. His concert, for instance, which he of course invited Athrun to, even if it wasn't exactly Athrun's sort of thing, but he wanted to be a supportive boyfriend nonetheless.
But the shore leave was short, and soon enough they had to return to the ship, once again, to return to chasing the Archangel. They were both rather refreshed from their short leave, and it was nice. But it also a return to the same old routines they were oh so used to, a neverending barrage of monotony and violence without much separating the two. They smiled at each other, sweetly, but secretly. The shore leave and made them relax again, naturally. They tried to hide it, they wanted to hide it, but ultimately it shown through. Even Nicol, who had been so worried about it previously, began to loosen up a bit. But they still kept it secretively enough to make sure that no one figured it out. They conciously avoided monopolizing each other's time, being sociable and friendly enough with everyone on the ship, and of course, doing their duty as soldiers. It was a difficult thing to manage, completely separating all three of these lives on this one ship that often overlapped nonetheless, but they did it. They knew that they had to. Even with their relationship and other parts of their lives, it was a time of war and they were both tasked in a different mission.