Stedman Graham is ''dedicated'' to Oprah Winfrey's ''happiness'' and he believes that is the secret to their happy relationship.

The 68-year-old businessman-and-writer - who has been with the media mogul for 32 years - has opened up about his and Oprah's happy romance, which was sparked when they first met at a 1986 charity event, and the businessman has revealed that the secret to their long-term partnership is ''wanting the best'' for one other and being able to ''self-actualise'' each other's potential.

Being interviewed on 'The Ellen Degeneres Show', he said: ''The thing about our relationship is I want the best for her. So, I'm dedicated to her happiness, so that's great for her and I want her to be the best she can possibly be and she's done a pretty good job of doing it. For me, I've been able to find my own happiness, and develop my own skills, my own talents, my own abilities - and I'm satisfied with that. So, the combination, when you have a good partner that's able to self-actualise their potential and you're able to self-actualise yours, one and one equals about six.''

Stedman also opened up about the TV personality potentially running for the White House in the 2020 Presidential election, and he believes Oprah, 65, would be the perfect candidate because she has the necessary qualities and always ''works very hard''.

He said: ''Oh yes, you can trust her, for one. She's smart, she has a photographic memory, she works very, very hard. She has qualifications to do it and she's very successful.''