I have a huge crush on my best friend's older brother. However, I'm worried he may think I'm too young. How do I show him I'm not too young for him?

Anonymous
The picture is representative of my fantasy. Its unfortunately not actually us
The picture is representative of my fantasy. It's unfortunately not actually us
My best friend's older brother is super smart, super funny, and super sexy. He's super easy to talk to and we always have a ton of fun when we're together. Needless to say I'm utterly smitten with him. In fact, I can honestly say I have a bigger crush on him than any other guy ever. I really, really, really want to find out if he's interested too/see if he wants to get together (because I sure as freak want to!)
However, there is a major problem that makes me worried: he may not give me a real chance because I'm so much younger than him (he's 31 and I'm 19).
Now for me the age difference is actually a major plus. I've been on the dating scene in my age group ever since I was 15, and I've got to say guys my age really suck. They're usually really selfish, immature, have no interest in commitment (I don't want to get married soon, but I want something more than a fling/casual relationship), and are often just interested in getting in my pants. I've decided I would much rather go for an older, more mature guy whose got his life together and isn't afraid of a healthy level of commitment.
However, if he doesn't have an open mind about the age difference I have 0 chance with him (even if we'd be amazing for each other) I'm worried that if I really try to find out now he'll just write me off as just being his baby sister's best friend who is way too young for him without giving me a real chance. Over the past year-ish I have caught him checking me out quite a few times, so that does tell me he at least finds me physically attractive. However, even if he finds my looks attractive he might still think 'she's really cute, but she's still way too young for me/in way too different of a place in life'. What can I do to show him I'm not too young/mature enough to be with him/not write me off just because I'm in a different stage of life?
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*I realize I may sound like some crazy boy obsessive girl, but I promise you this is very unique. I have never liked a guy this much and I so super badly want a chance with him.

*Also, I've told my boyfriend about my crush. She's super hopeful he'd give me a chance. She hasn't told him anything though. I'm pretty confident he has no idea how much I like him.
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Also, how exactly should I dress around him? I've been trying to dress sexy around him, but not slutty (as I want him to feel a certain sexual attraction towards me yet still not view me as "easy" or just some sexual object). What do you think is a good balance where I'm maximizing my sex appeal around him in a way that screams 'hot/sexy girlfriend material' and not 'slutty easy hookup material (but not girlfriend material)'?
I have a huge crush on my best friend's older brother. However, I'm worried he may think I'm too young. How do I show him I'm not too young for him?
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