During the show, we see the two in a joint therapy session discussing Dean's admitted infidelity.
"I wasn't attracted to her. It was just a warm body," Dean said of the woman he cheated with, identified as Emily. "I felt like I was on auto-pilot."
That led to an emotional chat about Tori and Dean's sex life.
"He was just never happy. Our sex life was never enough. I thought he was really happy with me," Tori said tearfully. "At the end of the day, it still makes me feel reall bad about myself...I wasn't good enough."
Dean then opened up about his own insecurities.
"I feel like a fat-assed, small-d--ked... zits on my back, piece of s--t," Dean said.
The next day, while making dinner for the couple's kids, a family friend asked Dean why he "jeopardized" his marriage.
"Because I didn't think I would get caught," Dean replied before revealing that he had been admitted to a psych ward for his depression after his affar was exposed. "I wanted to die. I was going to take my own life."
Michael Kovac/Getty Images for John Varvatos
Later, back in the therapist's office, Dean and Tori read the letters they had written to each other as part of a "homework assignment."
But Tori's found Dean's note lacking in "remorse," prompting Dean to clutch his head and emotionally say, "I feel shame. I have never felt shame before. You were at a Christmas event and I was f--king around. That's disgusting. I can't go to that hurt. I can't."
Tori reacted by telling the therapist, "He's not OK. This is not OK. He can't handle it. I don't trust that it's OK at all."