Whitney Houston's mother Cissy Houston is making the rounds to promote her lip-twitching memoir about her daughter -- this time on 'Oprah's Next Chapter,' where she brought along her son Michael Houston to divest himself of a secret.

In the episode, Michael admits to Oprah Winfrey that he (and not Bobby Brown) was the first person to introduce his baby sister to drugs.

Michael told O that he feels “responsible” for Whitney's death, saying, "I'm living, but I'm not alive without her ... I just felt like I should have taken better care of her.”

According to him, he wasn't aware just how detrimental the drugs could be and “things got out of hand.” As he explained, “You gotta understand at the time – the '80s – it was acceptable ... We didn't know.”

Whitney died on Feb. 11 of last year from drowning and what the coroner said was damage to her heart from prolonged drug use -- and Michael feels at fault.

“I gotta live with [it] for the rest of my life," he said. "It's painful ... I feel responsible for what I let go so far."

More From Hot 975