In a new interview on My Next Guest Needs No Introduction With David Letterman, the comedian and daytime talk show host, 61, opened up about being sexually abused by her stepfather when she was 15. DeGeneres, who first went public with the abuse claim in 2005, said he used her mother Betty DeGeneres’s breast cancer as a way to perpetrate the abuse and admitted she’s still hurt that her mother didn’t initially believe her.

DeGeneres told Letterman that her stepfather groped her breasts while claiming to be doing a breast exam, recalling, “He told me ... that he'd felt a lump in [my mom’s] breast and needed to feel my breasts because he didn't want to upset her, but he needed to feel mine.”

She continued, “Because I didn't know about bodies, I don't know that breasts are all different... 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.”

Things exploded when he tried to get in her room — DeGeneres previously said the abuse escalated into “other things” at that point — and she locked him and escaped.

“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,” DeGeneres said. (She spent the rest of the night in a hospital.)

DeGeneres said that her mother is now “apologetic” that it happened, but she didn’t initially believe her and stayed with the man for nearly two decades.

“I should never have protected her — I should have protected myself,” DeGeneres admitted. “And I didn't tell her for a few years and [when] I told her ... she didn't believe me and then she stayed with him for 18 more years.”

DeGeneres said Betty “finally left him” all those years later “because he'd changed the story so many times.” He was deceased by the time DeGeneres first went public with her story.

DeGeneres, who has been married to Portia de Rossi since 2008, admitted that it’s something she’s still coping with.

“I always have taken care of her my whole life,” she said of her mother. “So I just kept taking care of her. I didn’t really let it get to me. Until recently, I kind of went, "I wish I would have been better taken care of. I wish she would have believed me.”

She called it “a really horrible, horrible story” and said the “only reason I'm actually going to go into detail about it is because I want other girls to not ever let someone do that.”

When Christine Blasey Ford testified last year claiming that then-Supreme Court nominee Brett Kavanaugh sexually assaulted her, DeGeneres and her talk show guest Busy Philipps spoke about being survivors of sexual assault with Philipps describing it as “sadly the most unoriginal horror.”