This is a late response, but I felt compelled to comment.
It is a bit hard to play psychologist based on limited information, but some of the things you mention her saying and doing sound to me like they belie some interest on her part.
I understand that you are very self-conscious about what she thinks and are having a lot of trouble revealing this fully to her. I get the impression that you are both being too timid about stating what you want.
Here is why I think that. She has brought up the idea of anal play on several occasions unsolicited, even teasing you about it(a way of flirting with an issue). She has shown that she is fine with you doing it, and she even went to perform it on you before being stopped. I would brush aside her comments about it being "gay" and having you "lock the room when you do it" as her way of trying to either mask her own interest or tease a response out of you. I had a girlfriend who was really into anal play(although I wasn't,
and didn't trust her anyway) and she said a lot of similar things as
your girl. It is obviously a serious relationship that she cares about and perhaps she is hesitant because of that, but she seems receptive enough that if you can trust her and stop being scared off about the issue, I suspect you can both get what you want.
I really don't think you should leave it like this, and I hope that if you haven't already, you try to develope your trust of her and meet each others feelings on this issue.
@sensitiveguy22 I went back and read this thread again, and you mentioned mutual masturbation for those not comfortable with masturbating themselves. Well @artform has a blog on this site, he talks about the Wedding Band position, I think that would be something worth trying with your girlfriend. the post is found here https://community.aneros.com/blogs/ecstatic-energies-and-the-art-of-living/ title is wedding band position (scroll down). Hope it helps!!!