Young men trapped eternally in "friend zone" also still do this. Go ahead, get that door for her. Then she's totally going to stop thinking of you as a non-sexual confidant and be interested in you. "You're so good to women, you should have a girlfriend!"
...good point. My advice is to just hang in there and keep doing what you're doing. One day you'll find that perfect girl who is just like your mom and she'll love you and tell you're a gentlemen and try and cut off your penis because Satan put it there- Just like your mom.