There is more than enough reason to take action, to tell her, to let the truth out instead of trying desperately (and vainly) to hide everything.

1) I know you care deeply for her and I believe you understand perfectly that this friendship between you two matter as much to her as it does to you. You're afraid of losing this friendship, which is why you prefer to retreat to the safety of stagnancy and give things so much time that you can numb yourself into believing that they will just work out on their own, or that overtime your perceptions will amount to a clearer vision of the big picture and you'd be able to forge much more adequate plans. While I can't say I fully approve, I understand that perfectly. But what about her? At some level, she's probably convinced herself that she's already lost your friendship, that you've left her, that you don't care for her anymore, and I don't think we can deny that at least some of our actions over the past few weeks must have made her feel alienated whether we're conscious of it or not. Like I told you not too long ago, she has gotten so sensitive that even the simplest and most innocent of actions (such as us sitting together during class) would trigger much suspicion and over-interpretation on her part. If you take the effort to really observe, it's not difficult to see. We've already tried hiding. We've succeeded at times, and failed on some occasions, but you've got to see that we don't have unlimited chances or 'trials'; there's only so much we can hide, and we can't do it forever. Small things, little things, are going to leak whether we like it or not. We're trying to hem in water with a fence. It's futile. 

2) Don't forget the original objective of our decision to hide everything from her in the first place: to protect her feelings. This limbo state is doing anything but that. We're hurting her, Yu Xuan. We both know all too well how much the truth hurts, and I can imagine just how much pressure one would have to bear to tell her everything from start to finish, to dash someone else's hopes especially when you know that you're partly - if not wholly - responsible for it. The thing is, the longer you keep it from her, the more it's going to hurt when she finally finds out. It's going to be worse if she finds out not from your mouth but from the grapevine, because then her perceptions of you would be adversely affected; it's highly possible that she would interpret your kindly intentions as something akin to nonchalance, disloyalty or even spitefulness. When that happens, the exact manifestation of our goodwill - our constant hiding and deliberate shielding of the truth - is merely going to add salt to the wound, because the better we hide our relationship and act as if nothing's going on (and we're both very used to hiding, fairly competent too), the more abrupt and unreasonable your 'change of heart' would seem to her, and the more fickle she would perceive you to be. It's possible that she would think of your take on friendships and relationships as superficial and insincere, when it's the exact opposite of that. Don't forget that before all this the two of you were extremely close and spent a lot of time together. Don't forget that you were the one person who paid the most attention to her in New York. Don't forget that you've once expressed to her similar if not the same notions of dedication and support as you now do to me. With all these in your common past, don't you think it would be extremely perplexing and painful for her to feel neglected and yet nonplussed for a long period of time, to be perplexed at the sudden great disparity between the signals you used to send her and the ones you do now, only to find out that you've been keeping her in the dark all this while without 'bothering' to release her from her confusion?

3) You wonder why she appears so cold and aloof, why she's pointedly ignoring you, why she appears so pissed and dejected lately. On one hand, I shall very honestly say that I do not approve of the way she's being so possessive and rather unreasonable; it's perfectly understandable if she's hurt and doesn't hesitate to make it known, but expressing it in the form of hostility and acting as if you're obliged to devote all your time and energy to her is another thing altogether. Because you aren't. If someone tells you that he'll always be there whenever you need a shoulder to cry on, it is only naive, selfish and unjustified, and perhaps to some extent blindly desperate, if you bind him to such a promise and fervently believe that he would keep it. If you really do love a person in any way, one of your chief concerns should be about respecting his own freedom, time and space, and I don't think she's doing it. But on the other hand, I believe that she may be adopting this hostile attitude towards you precisely because she's confused and frustrated. Remember all that bullshit between YanYong and Ahmad? Just as I thought, it was all a massive misunderstanding stemming from a lack of communication between the two of them, drawn out by uncertainty, suspicion and hesitation on both sides. This is something similar...or at least it's going to be. What I know about Yunteng right now is, of course, far too little to make any well-informed judgment, but at least I think it is clear that for all her defensive set of cold stares, hard silences and ostensible evasion, what lies underneath is most likely a mixture of unspoken desire, hurt feelings, confusion, frustration, doubt, insecurity, hopelessness, and desperation. The way she feels entitled to your time and attention could even bespeak a desperate attempt to convince herself that you'll go back to her after what she believes is a temporary diversion. Like what I mentioned before, she thinks you've left her for something she doesn't know, but she doesn't want to believe in the prospect of you really having done so. She tries to hold on to you but you unknowingly shake her off, like that time in art room this Monday when you left her to sit beside me (even if it may be because your pencil-case was beside mine). This prolonged limbo is just making it worse.

4) I'm not sure if you realised, but this no longer just concerns the three of us (you, yunteng and me). The whole art class is starting to get dragged in bit by bit over the past few weeks, starting from people like Batara, Yanyong and Eugene etc. People aren't obtuse, and they most definitely aren't oblivious. Anyone can tell a feeling of tension apart from an air of complete ease, not to mention it's even more palpable when two people who used to be so close together are now appearing so distant from each other. What Ahmad was worried about is the fact that Yunteng, while rapidly beginning to warm up to 'new' people who have been friendly and caring towards her lately (like Batara and Ahmad), may be unconsciously drawing sides in the art class...something which could aggravate the sense of division that is already growing in the art class as of late. And I agree with him on this. The art class is so small. We can't afford to split up any further.

  Ahmad and Yanyong said they thought you were selfish, jeopardising the harmony of the art class by not wanting to tell the truth and let things out into the open for 'personal preference', but I know that your hesitation right now is not owing to selfishness because I understand your reasons. I know you're scared. I know it's not easy. I know it's hard to make a decision and go for it when it's something so exasperatingly delicate. But please, Yu Xuan, please. There isn't time anymore. There's no time at all. We've already deliberated enough and lost that window of opportunity to tell her when she was in a good mood, which was some time last week. Now your friendship is very visibly strained...and we're really worried for the two of you. I'm not talking about my happiness here. I'm talking about yours, Yunteng's, everyone else's, and subsequently mine.

  You told me earlier in the year that you prefer to deal with things when they're out in the open. You told me you want people to stop hiding things from one another.

  What are you so scared of? What's holding you back?

  There's nothing that can't be solved even if you screw up; at least you can pick up the pieces, rearrange everything, and we'd be getting somewhere. But one thing that's certain is that this will never be resolved if you don't do anything. It will just get worse. Worse, worse, worse and worse.

  Tell her, Yu Xuan. Tell her. Not one day, not someday, not soon, but now. Don't delay it anymore, please, for the sake of both of you and the art class. I'm here. I'll support you. I'll be there when you take the next step as well.

  ...because I love you, and because I love you, I want you to muster the courage and find the strength to resolve this and make things better for yourself.