Relationship Miscommunication

     So one of my really close friends was trying to talk to me about her boyfriend the other day. The boyfriend happens to be one of my friends from high school, so I know him reasonably well and don't really respond how she wants to her complaints about when he does the things that are truly unique to him. At first I just took it in stride--he's my friend and she's my friend, the two of them as a unit are my friends, not a huge deal.

     Apparently it's a much bigger deal than I thought. He and I decide to take a break from the shopping of a recent trip we made to visit her and go to dinner. We're sitting there in the pub in Portland, it was a really nice pub by the way, and he brings up that she complains to him that she can't gossip about him with me. I'm sitting there thinking, Well, duh, I've known you for about three years longer than I've known her, and he brings up the same point! I don't quite understand why it's such a big deal to everyone else that I know him as well as I do. We continue talking, and the girlfriend calls. She and my sister (who came down too) are done in the mall and want to know where we went, he gives them directions and they walk over. It's still not a big deal to either of us. 

     When they arrive she's obviously angry, or frustrated, or out of sorts with him and neither he nor I understand why. At first we just think it's that we didn't stay at the mall, then it's that he had a beer and she didn't want him anywhere near a car, then he suggested maybe jealousy; it wasn't until my sister explained that my friend's plans had been completely changed and taken out of her control that made her so out of sorts. I still don't know if he ever figured out what was going on with her, but they were pretty deep in conversation when we skedaddled. 

     My question is: how can something that is so small or innocent become a big enough deal to ruin one person's entire evening? I'm not a shopper and my friend and my sister are, he and I haven't had one-on-one time since they started dating and we were catching up. If we had known that she intended to continue with their double-date plans (even though the other couple had to cancel/postpone) the entire night would have turned out differently.

Just a thought....
Stephie