The glamour model, who became the third person evicted from the series on Wednesday (January 16), said she was disgusted with the Hills star's accusation that she was out to seduce her "chubby" husband Spencer Pratt.
"I'm gonna knock that bitch out after what she said about me," Banghard told the Daily Star. "If she wants it then I'll give it to her.
"I'm no wh*re. That is such a horrible word and so not true. I've only ever slept with one man in my life."
She continued: "I'd never touch someone else's husband. I am not a home wrecker. And Spencer is just not my type.
"I certainly don't fancy him. He is chubby. I never said I wanted sex with Heidi either."
Banghard had initially stuck up for the couple - nicknamed Speidi - in her post-eviction interview, describing them as having "good hearts".
"I felt sorry for them because we'd all said some horrible things about their marriage and that can't have been nice to hear," she explained.
"But I said sorry and made my peace with them. I thought we were friends and would stay in touch. I've been a fool and so naive. Everything they said to me was fake."
Heidi and Spencer are facing eviction tonight (January 18) along with the entirety of the house after Neil Ruddock and Ryan Moloney broke the rules by discussing nominations.
The live Celebrity Big Brother eviction show begins at 9pm on Channel 5.
Photo gallery - Lacey Banghard's best bits: