Ahh, yes. Honestly, I'm usually the one in his shoes. Afraid to open up and immediately put up walls when I don't want to talk about a difficult subject. My girlfriend has done a wonderful job of helping me communicate through those times though and in retrospect, I can tell you that modeling goes a long way. She often opens up and doesn't ask questions, just allows me to listen. After that, she allows us to 'emotionally breathe' by giving space and time to think about it, and that allows me to come back with a clearer head and more willing to open up.

Like I said, everyone is different. It sounds like you two have a great relationship outside of this but you also recognize that this could be a deep rooted issue, which has been the case with me. Allow this to be a learning experience for the both of you, you'll come out even stronger on the other side.

Side note, if this is just about a place to crash, have you considered suggesting to your friend that he get his own camping spot as they're still available? It may be be a compromise with your boyfriend and still solve your friend's lack of a lodging spot.