VIDEO What was Dean McDermott addicted to?

The revelations just keep flowing! In a preview for tonight’s True Tori, Dean McDermott opens up to a friend about why he cheated on wife Tori Spelling with Emily Goodhand.

“I didn’t think that I would get caught,” Dean said to a friend of having an affair while he was filming a show in Canada. “I was drinking and using drugs, man. I was not dealing with things that happened to me in the past.”

When Dean entered rehab in January, he was vague about addressing “health and personal issues.” In the new clip, he admitted it was specifically related to alcohol abuse.

“I have a brain that wants to kill me. I have a brain that wants me dead. That’s how the alcoholic brain works and thinks,” he explained to his friend.

But, alcohol wasn’t Dean’s only problem. He was also addicted to drugs.

“‘I’ll have a couple of cocktails, do a couple of lines and shut it down after three lines. You can do that Dean,'” he said of rationalizing his choices. “But it just never works out that way.”

Although Dean hadn’t spoken about his struggles with drugs and alcohol before, Tori recently told Us Weekly that she “always knew” alcohol was a trigger for her husband.

“He wasn’t dealing with a specific addiction. Dean has a lot of personal issues from his childhood,” she said this month. “He needed to work on things he hadn’t worked on in 47 years.”

True Tori airs on Lifetime tonight at 10/9c.