HELP! Should I leave him if he's too shy?

Let me start off by saying this- I have no problems with a guy who's a little shy and bashful. It makes it a lot more meaningful when they finally open up to you, and you develop a bond of trust that you don't normally find in other places! 
Here's the problem. I've been with my man for two years now. He's always been pretty quiet, but he opens up to me. That being said, whenever I bring him to family events and gatherings with my friends, he immediately shuts down and doesn't talk to anybody the entire night. Whenever I ask him about it he gets upset and says that's just how he is. Like I said, it's been two years. What should I do? I love him, but I also love my friends and family, and he doesn't seem to be doing anything to fix the situation.
Thanks!