Friend Advice: What would you do?

Hey all,
having a dilemma about a friend's actions. Trying to decide: shady or not? Would like to get objective opinions from people who don't know me or the other person.

Here's the situation: two year friendship, no especially big issues until this one. Recently I started dating someone new and was very excited about the relationship. She and I met him at the same barbecue. I started dating him and things went very well for about a month. She knew we were dating, and used to ask about it frequently. She seemed genuinely supportive and happy that things were going well. One day, the guy notified me via text message that he was going rock climbing with my friend on Sunday so he wouldn't be available to hang out with me. This was news to me, so I asked when they had set this up. He said she and he had been corresponding about it for a few weeks. Also, news to me, even though I had been hanging out with each of them a great deal over the past few weeks. He then said that he hoped I wasn't mad, that he was only telling me this so that I could have a talk with her about the fact that he and I were dating and head off any awkwardness. I was completely confused by this, and couldn't understand why I should talk to her about it when she already knew we were dating. Keep in mind, this was all text, so it's not as if we were actually having a full conversation. He did not invite me to go climbing, and when I asked why I wasn't invited, he said that he didn't think it was his place to invite me since she had set the thing up. I later talked (very cordially) to my friend about it, told her I knew she was going climbing with him, and told her that he had sent me a few weird text messages about it, and I was confused. She laughed it off, and told me she was taking him climbing because he had repeatedly asked her about it and she was "doing it as a favor to me." I didn't know what to think about this, or how to react to it. My initial thought was that they were both being disrespectful to me scheduling alone time together without involving me at all. But I didn't want to overreact if I was just being paranoid. They went climbing, without me.

So for those of you who didn't mind reading that long winded narrative, what would you do if you were me? How would you view this situation? Shady, or no big deal? I would really appreciate your opinions!