OK a couple of times.
But here's the thing, just because you think he's better doesn't make it so. what do i mean. I can see that you, like many, have an inferiority complex. There are some who appear to be untouchable even, everyone singing praises for him at every turn, but when you know the person a bit more, then you realize that he's nothing much really (IE, all fluff and no substance)
So, A, you cant say he's better necessarily. What you must understand is you are different, not inferior. You have to find your niche, understand what your strengths are and understand that there are areas that you can do better than him. No one is perfect they say, and everyone has their unique strengths. Understand this, and you'll get a better sense of self-respect and confidence. Now confidence is important, because you can be a real nice guy for anyone cares, but without confidence, you wont be able to leave a good first impression on say a girl you like, and without that the nice-guy part cannot be expressed. So, 1st tip for you. Be confident about yourself. the reason why they say " girls fall for the bad guys" is very very simple. As an analogy, these guys choose to spend all their time and effort boosting their confidence-albeit in ways that are not what you might say, ethical,-instead of developing their character(IE, being a nice person). because they have the confidence to do things, and to chase after the girls they want. No girl wants to be be with someone who cant even believe in himself. trust me. In you have confidence and at the and can be the nice guy, "a winner is you" as they say.
But in any case. I'll say this. If she's already given her heart to him(IE officially decided to go out with him), then move on dude. there's a saying in Chinese i believe," there are always other trees in the forest" i mean, so what if it doesn't work between the both of you, it's not the end of the world. There's always a better one around the corner. I understand that the situation sucks, but the healthy thing to do is to pick yourself up, get yourself together and become a better person. Learn something new, pick up a new skill, learning an instrument for example. Improve yourself, make yourself more attractive in the process. Learn to get a healthy ego, and be self-confident(but don't be a cocky prick). Try to mingle more with girls, possibly make a few platonic female friends. Heck, there is a chance that one of them may catch your fancy in the future or the other way. who knows.(although, there is the issue of "the friend zone" for which i shall not talk about here). That way, you become more comfortable in talking to them.
However, if she's yet to be attached to him, then i say by all means go for it. All is fair in love and war they say. Seize the initiative and go up to her. life is too short to sit around and do nothing. that was one of my mistakes in the past. I was faced with exactly the same situation and i stood there and did absolutely nothing, with me wondering what could have happen if i did decided to approach her then . Don't let that happen to you. Don't live in regret, and if she does reject you, big deal.
In any case im rooting for you. Do update us as to the progress.