Oprah and Stedman, 65,
have been dating since 1986, and when speaking with TV show runner Shonda Rhimes last year on SuperSoul Sunday
, the 62-year-old star
revealed when she first realized she didn't want to get married. "The moment he asked me to marry him, I was like 'Oh, God! Now I actually have to get married?'" she recalled, adding that they agreed to postpone their wedding and then never spoke of it again. "But what I realized is, I don't want to be married."