Should I go for it?

I have this really good guy friend in my grade (11). We've been friends since elementary school and our friendship means a lot to me. We've NEVER. felt THOSE kinds of fattractions for eachother. But, I do have feelings for his older brother, who is now graduated highschool, and through the vibes and connection ( more later) I'm getting from him, I feel the feelings are mutual, but if I jump and tell him, I bet the relationship I have with this guy friend will be wrecked. Now, this older brother is the most accomplished and sweetest guy I've ever met. He's got all the girls tumbling after him, but he never dated. He's super sweet to everyone, so I could be overanalyzing these 'signs'. You be the judge. So here they are: He finds excuses to touch me, even if its just a graze. He was so into helping me be a better pool player and suggesting where to hit where and whatnot, for example. Our conversations get a little deep and I feel how he relys on me for some stuff. Here's a weird one, normally he's a pretty chill, private guy, but he would jump in on conversations I'm having with some other guys that he has no part of and only could jump in if you were doing a little evasdropping beforehand. And I do some gawking myself, but I can feel when his eyes are on me at times, and I caught him in the act as well. And the last sign is that when we talk, its hard to keep eye contact when he's talking but will study me intently when it would be my turn to talk. I've studied him when he talks to other people and he looks them in the eye, so it led me to believe he's nervous around me. Now I can bet, you probably think he's all over me, but just shy. But, put into thought he's never dated, and why with me? An undergraduate at the least. I've never dated, and the hardest person I ever crushed on(crushed on him for nearly 4 years now) was him, so I could just be overanalytical about it all. And I'm always hanging with his little brother. There's all the cons. Well, should I jump and spill, then possibly ruining the relationship with my guy friend, or let it die? Afterall, he's leaving for college at the end of the month.

since you've been doing some analysis, why not take a step further and ask around... just in case older brother's got something going on. MAYBE he has a crush on you. MAYBE he's a bit too shy (really? for an older guy?). MAYBE he's also thinking about the future, or ruining your relationship with his younger brother.. we don't know. But once you or him (older brother) takes that one step further, it's make or break.. or maybe you are really just over analyzing things and maybe your good guy friend since grade11 is really cool about it. But then again why are you worried if younger brother is really just a friend? :) cmon...