Troubled singer Whitney Houston's alleged crack addiction has turned her into a sex-hungry fiend, according to her sister-in-law TINA BROWN. As part of a two-week world exclusive, Brown - the sister of Houston's husband BOBBY BROWN - has revealed the full extent of the singer's drug problems to America's National Enquirer tabloid. After telling all about Houston's secret druggie life last week (ends31MAR06), Brown is now revealing how her sister-in-law's alleged drug habit has made the I WILL ALWAYS LOVE YOU singer sex-mad. Brown tells the Enquirer, "Whitney has a problem. She's got to have it. Bobby always tells me, 'If you only knew. She's with this one and with that one. It's no secret.' "I've seen her with a woman a couple of times. They were walking around without their shirts on when I came in the house." Brown claims Houston satisfies herself with sex toys when she's alone. She adds, "They are all around the damn house. She buys them at a porno shop in Atlanta. "She locks herself in the bathroom and you hear, like, 'Vroooom.' She smokes some crack and says, 'I've got to go...' She'll be in there for hours."