Is it that weird to do this for a girl?

One day my crush, her sister and I went to the movies. While I was buying them tickets for a movie that I was seeing separately with them, my crush was looking at a movie poster of a movie that she wanted to see for a long time and it was a horror\thriller. She then called my name in a sweet way and asked me if she wanted to see the horror movie with her when it comes out because all her friends are afraid to watch it with her. I agreed to watch it her when it releases and I could tell that my response made her so happy. When the day of the movie released I called her and asked her if she was ready to see it and she said she couldn’t because she was going to be in a play for school and she had to buy a dress. I then asked her again later in the week and she said that her play was tonight and she would be busy and that was the last time I asked her. That was three years ago and till this day I still did not watch the movie she wanted to watch with me. I know it sounds weird that i choose not to watch it unless it’s with her but she’s my bestie and I promised her plus I have deep feelings with her. I am almost positive she didn’t watch it as well and I know she wouldn’t lie to me about being busy.