I was told that one way to start to like anal sex was to have a normal sized cock shoved into your ass all well lubed up until it went in balls deep. That ment it needed to be done slow and patient. When it gets fully deep inside the cock needs to just stop moving all to gether and hold it self there and just feel the fun of it. The ass owner also should just lay still and allow the cock to spread the tunnel completely but slowly. It is best to keep it there for 1-5 minutes depending on the 2 people. You 2 should do this a few times to get to enjoy it. After a few times it will be feeling better each time. No fucking just holding the well lubed up cock deep inside. Wen this feels good and you can get to this point easy then you can start to move in and out some. Each time try and fuck just a bit more.
Both will feel so good the cock can work it self enough to dump a load Eventually you both will get to love it and want to have some more movement. You will get to the point that the fucking can be how both want it to be! And as hard and fast as you like it to be.
Wife wanted to try anal so we did reverse cowgirl and let her do all the work so she could get it in and make it feel as good as possible from the start. She did that for some time and began to enjoy it enough to maybe want to let a good friend do it with her the next time.
Good luck folks. Anal can be one of the most fun things on all those ass nerves as possible!