Try to figure out what your mental block is.

For years my wife would have anal sex with me because I wanted it not necessarily because she got anything out of it. There were rare times when she let her inhibitions go, and in those instances she LOVED anal sex. The problem was she couldn't get her head around the idea that liking anal sex didn't make her a slut, or what ever. In her mind only "bad girls" enjoyed anal sex.

Try these links they might help.

http://www.sexuality.org/l/incoming/aanal.html
http://www.goodvibes.com/cgi-bin/sg...ulesofanal.html

Also realise that anal sex isn't just sticking dick in ass. It involves everything from fingers, and toys, to analingus (oral anal contact). You don't have to pound ass like a porn star to have anal sex.