she said she would try it on several occasions but when its time she backs out why does this happen?
Most Helpful Girl
It seems to me that she does that because she feels pressure from you to try it and she wants to please you, but in truth she doesn't actually want to have anal sex. Which I can hardly blame her for. Some girls do enjoy it but for many it's painful or very uncomfortable at least.
To many people the idea of anal sex is a downright terrifying prospect. It's possible for it to cause damage even when done correctly. And it's more likely to be painful or result in damage if she's afraid or reluctant. This isn't something that should be done simply as a favor to you. It's far to serious a matter for that. It needs to be a mutual desire.
You have every right to ask if it's something that you want. But you should read between and take her hesitancy as a no, at least for a while. Since you wouldn't want anything up there, you should understand why she doesn't.