1:00 PM EST, February 16, 2012
INSIDE EDITION is getting an insight into the tensions and turmoil of Whitney Houston's private life, from someone who knows the family very well.
Zach Jafarzadeh dated Houston's daughter, Bobbi Kristina, for more than two years.
"There was a power struggle at that household," Jafarzadeh told INSIDE EDITION's Diane McInerney.
He would spend hours hanging out with Houston and Krissi, as he called Bobbi Kristina, at Houston's mansion in Atlanta.
He said Bobbi Kristina loved her mother dearly but they would have major blowups.
"They would fight, they almost felt like they were sisters," said Jafarzadeh.
McInerney asked, "What would they fight over?"
"Anything. If there wasn't milk in the refrigerator or something. There would be an outburst," responded Jafarzadeh.
Jafarzadeh says he never saw Houston do drugs but was aware from his time at the house that it was a big problem.
Jafarzadeh said, "Everybody knows Whitney had a drug struggle. She had a hard time with drugs and it was obvious in the house that that was happening."
McInerney then asked, "In what way was it obvious that Whitney was battling drugs?"
"There would be days when she was extremely ecstatic, happy, being outgoing having a good time, and next day, sad and down, on the couch watching TV all day," said Jafarzadeh.
Strangely, Jafarzadeh said Houston and her daughter had a role reversal.
"Krissi was the parent sometimes. She always looked out for her mom. Anything that was going on with her mom, if her mom felt sick, was down for the day, Krissi would comfort her mom, talk to her, try to get her to go out," said Jafarzadeh.
Bobbi Kristina herself hit the headlines last year when the National Enquirer showed photos of her reportedly doing cocaine.
Jafarzadeh admits he leaked the photos to the Enquirer and now regrets that decision. He said, "I wish I had never done it. If I could say anything to Krissi, I would say, 'I am so sorry for any stress I caused her.' "
Jafarzadeh says Houston allowed her teenage daughter to drink booze.
"She'd rather have Krissi at the house drinking, than out partying and drinking, getting in trouble," said Jafarzadeh. He continued and said, "If she had let Bobbi Kristina go out and do what she wanted to, I think it would have been a lot worse."
Jafarzadeh says he knows the heartache his ex-girlfriend is going through now after losing her mom.
McInerney asked, "Did she want to be like her mom?"
"Yeah, of course. She looked up to her mom so much, her mom was huge, she was the best, she had so much personality. They really had a very extremely close relationship. Krissi needs her right now," said Jafarzadeh.