Also, be patient. Be prepared for it not to work the first time. The first time I tried anal sex, it was like trying to put my fist down a drinking straw. I actually pushed her across the bed a little. If it doesn't happen, just have normal sex and try again another time, talk about what worked and what didn't, and just relax.
From there, more communication and practice (which is fun!) is what worked for us. I asked what she liked, she told me what was good and what wasn't. Before, during, and after. Good luck!
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