Her first intimate experience

A long time ago my wife and I were having the house to ourselves as our kids were at a sleepover. We were in bed and she was riding my face. She was really getting into it sliding back and forth, then she slide up so far that her anus was over my lips. I didn't stop so I keep licking. I heard her gasp and then she went back to riding my face. After awhile she slid up again. Her anus again over my tongue. This time I held her in place as I rimmed her anus with my tongue. As I started to tongue fuck her anus she asked if I'd fuck her in the ass. Of course I said yes and we quickly change positions. I grabbed some lube out of the night stand as she got on her hands and knees. I told her to put her head down on the bed and ass up in the air as I positioned myself behind her. I lubed her asshole using one the two fingers. Then I applied lube to my hard cock. I pressed my cock head against her anus and is slowly went in. Once the head of my cock was in I told her to push back when she wanted more of me in her. After a few pushes I was all the way in. I paused for a few seconds and told her to relax as I slowly started to fuck her. Soon she was pushing back and I was fucking her ass. She came the hardest and loudest of our marriage. Since then we have anal sex about once a month...