• Share
  • Tweet
  • Share

Dean McDermott is a man who has hit rock bottom.

In January, Dean "voluntarily" checked into rehab to seek treatment for sex addiction after reports surfaced that he cheated on Tori Spelling in December 2013. Now, in a sneak peek at Tuesday's all-new episode of True Tori, Lifetime's new reality hit focusing on the couple's attempt to save their marriage, Dean is finally revealing why he cheated on Tori during a revealing conversation with his friend.

"I didn't think that I would get caught," he admitted. "I was drinking and using drugs, man."

Whoa, talk about getting real on reality TV.

Dean then goes into detail about his addiction to alcohol, saying, "I have a brain that wants to kill me." But what did Dean have to say about the couple's sex life prior to his cheating? Watch the sneak peek above to hear Dean's unfiltered conversation with his friend about his affair, his addiction and more.

Though Tori recently opened up about her marriage, writing that the family is going through "a difficult time," E! News exclusively reported that Dean was by Tori's side when she was secretly hospitalized for six days. "He would arrive by 10am and didn't leave until 8 most nights," a source said. "He seemed very stressed out and worried. He would bring food and often only left Tori to go outside to catch some air or make a phone call.''

True Tori airs Tuesdays at 10 p.m. on Lifetime.