I don't think its exactly about convincing her to do. Some people really are not into that sort of thing. Have you tried talking to her about it? I mean you're in a relationship so you should be open enough to discuss anything, especially what happens sexually. Let her know its something you really want to try and see how she responds. I don't suggest just keeping on trying it like sneaking it in there because that eventually is going to become a big deal to her
Many people recommend the book "Arouse Her Anal Ecstasy" as a great guide to pain free, orgasmic anal sex.
Wow!! Nice post, i agree with you, books gives the information of sex that is very helpful to you during the sex with your partner.
i agree with backdoor man in a way, i think it sucks and is selfish of her to treat u like that, if u like anal sex then she should do it for u
If convincing is necessary, don't do it. Ask your girl, either she wants to , or she doesn't. Don't be a dick. Your ass is the same as hers. Think about that there bud.