"The decision to do this show is not coming from someone who is in a solid, good place. Tori is very, very upset and angry," a longtime friend of Spelling's says in this week's issue of PEOPLE. "It's just too raw and personal. There's too much pain and it's too private."
Adds the source: "A part of her wants to completely humiliate him and make him suffer in front of millions of people. She wants to have some sort of justice. She wants him to truly feel the pain of what he did to her."
The couple began filming just days after McDermott left rehab for sex addiction and will continue shooting for six episodes of True Tori.
The docuseries, which will premiere on Lifetime April 22, "was all Tori's idea," says the friend. "She's in a total crisis mode. If she can believe that his addiction has nothing to do with her, then maybe they can move on. But there's no way Dean wants to be humiliated on television for cheating on his wife. His life is basically a nightmare."
In the series, McDermott pleads with Spelling to let him return to their house after rehab. "My life means nothing if you're not in it," he tells her.
A source close to the couple says McDermott is now staying at their home but primarily for the sake of the couple's four young children.
"They are focused on their kids," says the source. "Tori doesn't consider her and Dean back together."
As for the future of their marriage, "Dean will do anything Tori says right now," says her friend. "And what better way to ensure that he will never cheat on her after this? I don't think he'd ever want to go through this again."
For more exclusive details about Tori Spelling and Dean McDermott's marriage crisis, pick up this week's issue of PEOPLE, on newsstands Friday