I have always done that, with all my partners, it just felt naturalI wrote about this in another thread, so I'll be brief.
I was dating my boss. She was a couple of years older. We keep things rather discreet. At the Christmas party, we danced and flirted with others for the "illusion." We were both horned up and rushed back to her place as the party wound down. Being so horny, I lasted only 10 minutes and came before she did. She said that she was so close that I had to finish the job and shoved my head down to her pussy. I had tasted my own cum but never out of another person. But I really enjoyed it and so did she. It became part of our regular play.
Not a lot of women I dated since liked the thought of it but the few who did found the act to be not only highly erotic but also highly comforting in the sense that I'd do something for her (and me) that many men won't.