Promises are made to be broken; just like rules. No, I still don't believe that; if you make a promise you keep it. Yet when love becomes thrown in the mix, the promises you once made can be threatened. You never plan for that to happen; we tend to always underestimate the power of love.
The problem is that when you make a promise, it's a conscious thought; you know what you're promising at the time. Nevertheless, as time goes by, your feelings change for that person; even if that means they just become deeper. You know what you feel can, and most likely will, get you in trouble; yet it's love, you need to embrace it.
What do you do when a friend asks you not to feel that way about them? Or at least not act on it. You love them like crazy, not in love, but as I have been known to say; being in love and the love you feel for a good friend is separated only by a very fine line. In this case, say one friend just wants to be casual friends, while the other loves them deeply; they're the kind of friend you want to talk to everyday. Of course, in wanting to keep the friendship in good spirits, you make that promise. At the time you feel as if you have no choice; indeed, you mean it what you say. Overtime, however, your love for them only deepens, and you begin to long for a deeper relationship. You still think of them only as a friend; there's no sensuality involved whatsoever, yet you begin to wish you hadn't made that long ago promise.
For now you're stuck; you can't "unlove" them, nor can you go back to just thinking of them casually. It's too late for that now; they are firmly embedded in your heart. If only you had been up front with them, and them with you, about what you each want out of the relationship; what role you will play in each other's future. Alas, love doesn't work like that, for if you were to have had that discussion back then, it would've been useless anyways. When you first were in the early stages of the relationship, just getting to know each other a bit more, you didn't love them like you do now. There was no way for you to predict how you would feel in the future.
The only direction you can go from here is forward; unfortunately that has been shown by many to mean parting ways. That's the wrong thing to do most of the time; it will only hurt both of you. You need to be patient, you need to talk with them a lot. To see if there's a happy resolution to this problem, the only way you can do that is to tackle it from every side, so to speak. Both of you need to sit down and talk about where your feelings stand in the relationship, and most importantly, what you both envision for a future. Full and complete understanding of emotions in a relationship is essential if it's going to last.
It's only once you do this; once you have talked about it for so long, analyzed it from every angle, that you can make a decision. That doesn't mean, however, it will be one that leaves you both happy and satisfied. Sometimes you will realize that you will always have that gap between feelings; it will only get wider as one of you tries to close it, eventually causing one or both of you to fall. In which case, the only course of action to take is to part ways now; to leave with a tearful goodbye for both of you, instead of only one of you.
Love is by no means something easy; that's why most of the time it doesn't work out. Yet you can never give up hope and stop looking. For there's no other feeling to match that one in life; when you love someone and are loved back in the same way. When you have found that feeling, that is true happiness.