“He tries to break my door down, and I kicked the window out and ran.”

Ellen DeGeneres has opened up about a traumatic experience in a revealing new interview.

Speaking to David Letterman for his Netflix series My Next Guest Needs No Introduction, the Emmy Award winning host recalled when her mother, Betty DeGeneres, married a “very bad man”.

Shortly after they married, her mother was diagnosed with breast cancer, which led to the man sexually assaulting Ellen.

“He told me when she was out of town that he’d felt a lump in her breast and needed to feel my breasts because he didn’t want to upset her, but he needed to feel mine,” she revealed.

“Again, ’cause I didn’t know about bodies, I don’t know that breasts are all different and… Anyway, he convinced me that he needs to feel my breasts and then he tries to do it again another time, and then another time.”

She continued further: “He tries to break my door down, and I kicked the window out and ran ’cause I knew it was going to go more to something… and I didn’t want to tell my mother ’cause I was protecting her and I knew that would ruin her happiness.”

Ellen said she felt “angry” at herself for being “too weak” to stand up him, despite being just 15 or 16 at the time.

“It’s a really horrible, horrible story and the only reason I’m actually going to go into detail about it is because I want other girls to not, you know, ever let someone do that,” she admitted.

“I should never have protected her. I should have protected myself and I didn’t tell her for a few years and then I told her. And then she didn’t believe me and then she stayed with him for 18 more years.

“And finally left him because he’d changed the story so many times.”

The second season of My Next Guest Needs No Introduction With David Letterman premieres this Friday on Netflix.

Related: The Ellen DeGeneres Show has been renewed for three more seasons.