Closer, but Ruder

I recently had a rather jarring experience. I discovered that one of my good friends is rude. This might sound ridiculously stupid, how can you not know someone is rude? But here's how it happened. I'd been planning to meet a few friends for lunch. One of us had even rearranged some activities and given up a favorite pastime to be there. While the idea was mostly just to get together, we also called it a late birthday celebration for me. Then, one friend didn't show. Called at the last minute, she'd forgotten this other thing, with another friend, sorry, see you some other time. More surprised than hurt, I said to the Husband, "Can you believe Shawna (not her real name) would blow us off like that?" The Husband looked at me like I must be kidding and then said "Are you kidding?" I looked at him blankly, what did that mean? He continued "Haven't you ever noticed that Shawna is totally inconsiderate?" I immediately jumped to her defense! She volunteers, she does this, she does that, she's such a good person. "Yes," he patiently "She is a very good person who does nice things for people, but she pulls this kind of thing all the time." He easily rattled off several other times Shawna has done this exact thing to me or our mutual friends. I was gobsmacked. I've known her for years, and it never really sunk in - she's just plain rude about this one thing. And, the better she knows you, the worse it gets - at first, she's late, but on her way or she gives you more notice. I guess her increasing rudeness in this area is a testament to her confidence in the friendship. The friend she blew me off to see - it's the one who doesn't call her to make dates, who isn't always available, who probably pulls the same thing on her. I'm not going to go down that path - I don't have it in me and I don't play games. I'll probably keep going on the way I have, but next time, I won't be surprised.