As the title suggests, I’ve never had much of an issue talking to and getting to know total strangers. But when it comes to meeting people from the lives of my friends, brothers, and most importantly my girlfriend, I basically shut down and talk as little as possible. 

In these situations, I pretty much only respond when people talk to me, instead of striking conversations with them, and even still I’m usually very short with my responses. I don’t know what feelings inside me cause this, or why I treat these situations different from interacting with total strangers. 

Anyone else deal with this? Any advice?