Oprah Winfrey‘s boyfriend Stedman Graham only has himself to blame now that the talk show mogul has ditched him, his mother told The National Enquirer.

We recently revealed that Oprah will leave Stedman behind when she moves from the Chicago apartment where the pair has lived together to her $55 million estate in California.

But, in an exclusive interview, his mother Mary Graham said the 18- year relationship would have continued if he had married Oprah. Speaking at her New Jersey home, widowed Mary gave devoted son Stedman, 54, a tongue-lashing for not popping the question to the 51- year-old TV tycoon.

The distraught mom said: “I never understood why he did not marry Oprah. I would be proud to have her as a daughter-in-law but Stedman never proposed. It’s sad to hear they may not be together anymore.”

Sitting at the dinner table in her green weather-boarded home, Mary said: “I was a bit nervous when Oprah first came here to eat but we got along very well. She and I come from very poor backgrounds and she has worked hard to become a success.”

Stedman’s mom Mary revealed that Stedman, who has a daughter from a previous relationship, never discussed marriage or children with Oprah. She said: “He never wanted to talk about it. I love Stedman but there are some things you don’t talk about with him. I first found out he was seeing Oprah was when a friend read it in a newspaper.”

Oprah and Stedman have spent the past 12 years living together after first meeting in 1987. But as The National Enquirer has reported, the relationship has suffered recently because the pair has been spending more time apart. We also revealed Oprah has been seen flirting with other men including Oscar winner Jamie Foxx.

Stedman told Larry King in 2003 that constant traveling made “trying to fit in marriage” impossible. But his best friend from high school, John Robertson, doesn’t agree: “I hope he does what makes him happy but I think he should marry Oprah. It would be nice to see him walking down the aisle with her. They make a nice couple.”