Controlling best friend!?

I have 2 best friends, Mandy and Katie. Katie usually isn't controlling, but Mandy is. Katie usually just goes along with whatever Mandy says because she doesn't want her mad at her. I'm getting sick of doing whatever Mandy wants. For an example, we were going to do something before homecoming and I recommended doing something, she said that she thought it was a little much. Then a few nights after that she made reservations and I wasn't even aware that she was until she called and asked how many people she should make it for. She also asked me if I could go to a soccer game with her and I went because I'm a good friend and I like to do things for people that I wouldn't normally like doing. I honestly find soccer boring,but I still went. Then, I asked her to go to our schools sockhop after the football game one night. She didn't feel like going, so she didn't go. She always plans things too, but when I try to plan things she can't come, and neither does my friend Katie. How can I talk to her about this? Or am I being absolutely ridiculous?