Furious Bobby Brown has accused Whitney Houston of cheating on him with one of his best friends -- and even shouted that Whitney's lover is the real father of their five-year-old daughter.

A source close to the couple was astonished to hear Bobby scream at his beautiful wife that she was sleeping with his ex-bandmate Ralph Tresvant.

"Bobby got in her face and shook his finger at her accusingly," says the source, who blames the couple's problems on cocaine.

[ tabloid mag cover pic] [ picture of WH #1] [ picture of WH #2] [ picture of Ralph Tresvant]

"He was exploding with rage. 'You ****ed Ralph! I bet he's really Bobbi Kristina's daddy!'"

"Whitney broke down in tears and started screaming back at him. 'I told you! She's our baby! I told you it's not Ralph's. She's ours.'"

The source, who has witnessed several battles between the couple, says he doesn't know if Whitney is having an affair -- but her relationship with New Edition band member Tresvant is a constant source of irritation for Bobby.

"Ralph comes by when Bobby is out of town," says the source. "He's seen Whitney three times recently, and they were close even before she married Bobby".

"Bobby is aware of it and is enraged by it. It's the reason he pulled out of a New Edition reunion tour last summer. And when he really wants to push her tons, he accuses her of lying about their baby Bobbi Kris -- he says he thinks its Ralph's child. I don't think he really believes it, but it's his way of throwing the relationship in Whitney's face."

The issue came to a head last summer when Tresvant showed up at a Houston family reunion in New Jersey, says the source.

"The reunion was a big affair, with people scattered everywhere, and they have a really big estate. But Ralph comes onto the property and one of Bobby's security people spots him. He phones up to the main house and gets Bobby, and tells him, 'Ralph's here, what do you want us to do?' Bobby said, 'He's not welcome here, get rid of him.'

"They used to be close friends, but Ralph's relationship with Whitney has driven a wedge into that".

"Whitney has always known her relationship with Ralph won't lead to anything, but she does what she wants. She believes she doesn't have to answer to anyone, including Bobby."

And the source blames Whitney's poor judgment on drugs. "Virtually anytime you see her, she's drugged up. She's so used to being drugged, she knows how to handle herself in public. It may not be apparent to the public -- unless you're right up with her, you don't know the effects the drugs have.

"It's caused her to be late for concerts and cancel appointments. She has a driver take her to a drug dealer's house to buy cocaine. She even got pulled over on a highway leaving Kennedy Airport in New York with a lot of cocaine in the car, but luckily for her, it wasn't found." Cocaine also makes her abrupt with people, says the source.

This article was from a tabloid. That means it is a fabricated story and should be viewed as such! DONT BELIEVE THE HYPE!

"She was doing a Whitney Houston Foundation for Children benefit around Christmas 1996. Of course there were a lot of kids there being kids, running around, playing.

"Whitney was called out on stage to present the kids, and they kind of overcrowded her -- they were really happy to see her. When she got back to the table, she told one of her handlers -- within earshot of a lot of parents -- 'I can't wait to get out here. They stink, they're funky and nasty, can we leave now?'

"People were just looking at each other and saying, 'How can she say things like that?' Even her mother Cissy told her, 'Child, you shouldn't be saying things like that.' But she didn't give a damn."

Meanwhile, Whitney's marriage has become a constant battle -- sometimes even ending in violence.

"Bobby comes out on the losing end of that quite a bit," says the source. "Whitney can take care of herself and then some. She has literally flattened him out, knocked him right on his seat. It sometimes gets to the point where the bodyguards have to pull her off him.

"Whitney and Bobby argue all the time. There always has to be a mediator to sort them out, usually Whitney's sister-in-law Donna. You wouldn't think it should be that way between husband and wife, but for them it is."

But no matter how much mediation goes on, it is Whitney -- as star of the family and its chief bread-winner -- who maintains the upper hand.

"It's even with small things like Bobby wanting a day out with their daughter. He goes to the house to pick up Bobbi, and Whitney goes running outside screaming -- so loud that the guard comes out.

"She says, 'Where are you going?' Bobby says, 'What do you mean, you know where I'm going. I told you, we talked about it.' and she says, 'Well, I don't want you to go now.'

"All hell broke loose. Bobby starts screaming, 'I'm tired of this s***. I do what I want to do, and I'll go anywhere I want to go. You're not going to stop me.' But when all was said and done, he still didn't take Bobbi-K."

Bobby's far from the only one to get the cold shoulder, says the source. Whitney has distanced herself from many family members -- including her mother, Cissy.

"When Whitney was taping the HBO special in Washington last fall, Cissy had just gotten out of the hospital after having knee replacement surgery," the source says. Cissy was wheeled up to Whitney's room, but one of Whitney's aides told her that Whitney -- actually Nippy, that's what they call her -- was taking a nap and didn't want to be disturbed. So Cissy is wheeled out, but Whitney sticks her head out the door to make sure she's gone."

The source says Cissy also showed up at her daughter's door after Whitney canceled out of a million-dollar performance at a Unification Church mass wedding last December. "Whitney called in sick - she was holed up at the Trump International Towers in New York City".

"Cissy went to talk to her about it, but when she showed up at the door, Whitney says, 'What are you doing here?' Cissy says, 'I want to see you,' but Whitney just told her she wasn't welcome and shut the door."

Whitney's press representative Lynn Volkman denies the star was rude to her family and says she never heard that Bobby believed his wife had an affair with Tresvant. She also says she has no knowledge of Whitney's escalating cocaine use.