Jo said he raped her “continuously” in “target practice” and kept a “score sheet” of his victims.
He modified her dad’s old donkey jacket into a rape suit – cutting out an inside pocket so he could hold his knife there while waiting to pounce.
Bellfield once took her to any alleyway where he said he would “wait for the bitches”.
When she tried to phone police he told her she’d be “f***ing dead” if she ever told anyone of his crimes.
“ It was just target practice for him for what he went out and did to other people. Beatings”
Bellfield, 49, is serving life for the murders of Milly Dowler, 13, Marsha McDonnell, 19, and Amelie Delagrange, 22.
He is recently said to have confessed to a fellow prisoner he also killed Lin Russell, 45, and her six-year-old daughter Megan in Chillenden, Kent, in 1996.
Lawyers for Michael Stone, 57, who is serving life for murdering the Russells, hope it will help clear their client.
But though she despises her ex-husband, Jo, who had two children with him, has reluctantly had to give him an alibi for the Russell murders.
She said he could not have done it because it was her 25th birthday and he spent the day with her 100 miles away in Twickenham, south-west London, and attended her party.
She said: ”You know he raped me continuously.
”The rapes – it was just target practice for him for what he went out and did to other people. Beatings.
”The point that he would strangle you or get you to the point where you blacked out was all target practice ‘cos then he knew how far he could go before he actually did something.
”He had sex with hundreds of women. Be it voluntary or not.”
”He was bragging how he’d raped a disabled girl the night before on a car bonnet in the car park, and it wasn’t on video because he’d taken the video out of the CCTV so it couldn’t be found.
”He would tell me because in his mind I was his slave.
”I was nothing to him.
”He knew I would never and could never say anything about it.
”It’s like living the worst nightmare over and over again.”
Jo said she discovered her husband’s sick secret when she discovered his rape kit.
”I found a bin liner that I found in my garage and it had my dad’s old donkey jacket in it, a kitchen knife, a balaclava, and on the inside pocket of the left hand side of the coat he’d cut the inside out.
”That’s where he could hold his knife when he was gonna attack someone.
”He told me that he used to rape people in the alleyway.
”But sometimes there were too many people around so he couldn’t and he used to get really frustrated.
”When he got frustrated he’d take it out on me.”
Jo said she was so terrified she dare not go to the police and instead suffered the beatings and abuse in silence.
”I firmly believe I tried to block most of it out because you, a, don’t wanna believe it, and b, you can’t believe it.
”It’s very hard, you know.
”Not only are you living with someone but when you’ve had kids with someone you certainly don’t wanna believe that they’re capable of…
”Even though what he did to you at home you don’t wanna believe that he’s capable of going out and doing it to complete random strangers.”
Michael Stone’s lawyer: Levi Bellfield admitted to Russell murders
”The testimony Collings gave us was that she believed Bellfield could not have committed the crime,” he said.
”She said he was at a birthday party that day.
”She was a witness for the prosecution in his trial and would be the very last person who would try to protect Bellfield.
”It was deemed credible enough at the time to rule him out.”