I usually don't use this for personal stuff but...

...when did saying you would do something with someone become an empty promise? Is it right to tell someone you are set on going somewhere with them and then a week later just say, "I can't. I'm going with someone else and there's nothing I can do." I don't think it is right. Honestly, if someone asked me to go somewhere with them but I had plans to go already with someone else, someone who is "first priority" i'd tell them thanks but no thanks. But that isn't you. You can't say that to a friend can you? You can tell me that you're sorry all you want but that doesn't change that you are leaving me alone to do the exact thing I wanted to do with YOU. Thanks a lot.