In the True Tori preview clip above, Spelling and McDermott are in a joint therapy session where McDermott is confronted about his affair and how it affected their family.
"It's creepy to think someone could be that good of an actor," Spelling says of McDermott's initial behavior. "This, to me, was done right in the middle of loving you."
While Spelling and her four kids were at a Christmas event, McDermott was allegedly working, but in reality he was "f---ing around." After Spelling confronted him, McDermott suddenly comes down with a headache "like an icepick through my head."
Spelling is overwhelmed by the pain McDermott seems to be experiencing, but the therapist urges her to continue to talk about her feelings and what McDermott's actions did to their family.
"I feel shame. I have never felt shame before," he says. "You were at a Christmas event and I was f---ing around. That's disgusting. That's disgusting."
True Tori airs Tuesdays, 10 p.m. on Lifetime.