How can I make an awkward situation less awkward when my dad is involved?

I like a man who works with my dad. He's similar in age to me (22) and my family likes him and his family. He's a twin and his twin is married and has a child. His twin is also more outgoing than he is. Here in lays the problem, he is very shy and doesn't talk much at all and when he does he's self-conscience because his twin is usually the one that gets more attention and he commonly thinks that people who are talking to him think he is his twin. I have even made this mistake once, in thinking he was his twin. It's very awkward between us because he doesn't really talk to me and he's caught me looking at him during functions. Also, he's metro-ual and I'm more of an indie rocker. My thrift store look doesn't really match his Ambercombie. It makes me nervous because I think he may think that he's higher cl than me. It doesn't help that I'm curvy like Salma Hayek and tall like Gisele B�ndchen and a ginger to boot. He's probably used to a girl who is more like Kate Bosworth. All-American girl. I usually mess up when it comes to things like this. I am also very shy and when I get nervous I usually make jokes or act like an idiot. I know if I mess up this time it could make it a mess for my family as well. I really want this to play out well. Any ideas?