During the weekend of December 7, McDermott was in Toronto as part of a press tour to promote the new reality show Chopped Canada for which he'll serve as host. While away, McDermott allegedly had sex with a woman named Emily Goodhand, who's come forward with guilt and regret to reveal details of their passionate weekend, Us Weekly reported in its January 6 issue.
"He told me he and Tori had a sexless marriage. I believed him," Goodhand, 28, told Us. "He was romantic and very complimentary."
In addition to having sex, McDermott and Goodhand allegedly spent the weekend cuddling, texting and ordering room service. McDermott was allegedly seeking companionship when away rather than just a one-night stand.
Goodhand admitted she had "made a stupid decision" to hookup with McDermott although the couple "absolutely" used protection.
"I'm sorry. I f-cked up," Goodhand said, ultimately apologizing to Spelling for the affair.
McDermott and Goodhand reportedly met on December 6 through mutual friends at Pravda Vodka House. The pair, along with six other people, enjoyed a two-hour dinner and drinks.
"We were just having fun and hanging out," Goodhand said. "He seemed like a cool guy. I thought he was handsome."
Afterward, the group headed to the bar at McDermott's Fairmont Royal York Hotel. During the walk over, McDermott began to show interest in Goodhand.
"He was flirting. His personality is very charming. I was drinking, so what he said is blurry. But he was talking about his kids and his work. And when people open up, you feel closer to them in some way. I felt like I could trust him. And we know a lot of the same people, so we had that in common," she explained.
McDermott has four children with Spelling -- Liam, 6, Stella, 5, Hattie, 2, and Finn 15 months -- in addition to a son named Jack, 15, from a previous marriage.
About an hour after the group arrived at the hotel and sat down for more cocktails, Goodhand observed McDermott silently and discreetly slipping his hotel key card into her purse. The pair had an unvoiced understanding.
"We just looked at each other," said Goodhand, who later discovered in her bag McDermott had also written his room number on a separate slip of paper.
Goodhand reportedly nonchalantly exchanged numbers with McDermott and left the restaurant around 11PM with several friends. After struggling a little bit with her course of action, Goodhand admitted she had made the "stupid decision" to enter McDermott's room. But much to her surprise, he wasn't present.
"I texted him and said, 'If you're not here in five minutes, I'm leaving,'" Goodhand told Us.
McDermott then reportedly showed up in under a minute and the reality TV star quickly put the moves on her.
"He was telling me, 'You're so beautiful.' I had to call him on his bullsh-t like, 'Stop saying this stuff.' He wanted to make me feel really good. Then the time for talking was over," Goodhand explained.
Goodhand said after they had sex, it wasn't long until McDermott brought up the subject of his wife.
"He said, 'I love my wife. I love her so much, but she just won't sleep with me,'" Goodhand revealed. "I didn't ask why because it was awkward."
Goodhand noted she felt like she had known McDermott much longer than 10 hours, but she opted to leave as the conversation about Spelling got progressively more uncomfortable.
"I don't get a good sleep if I'm not in my own bed with my own pillow. But he was like, 'Please don't leave me. I want to cuddle,'" Goodhand said.
Because of McDermott's request, Goodhand chose to stay the night. When the pair parted ways the next morning for work purposes, they allegedly texted throughout the day.
"He said, 'I'm tired,' and I said, 'My legs hurt,'" Goodhand acknowledged.
Thanks to a subsequent invitation to join him, Goodhand returned to McDermott's hotel room around 1AM on December 7. She arrived late because she "already had plans" that night. However, Goodhand was surprised to see McDermott had a male friend there as well.
When the male friend left the room for a moment, McDermott reportedly began showing Goodhand "pictures of his kids and stuff like that." Spelling was in some of the photos and Goodhand told the magazine she "was trying to focus on the kids instead of Tori."
McDermott then allegedly showed Goodhand a still photo from the sex tape he and Spelling had made back in 2009.
"Dean says, 'Oh, wait until you see this! Tori and I did a sex tape.' I look over at the screen at a frame of Tori lying on the bed. I'm like, 'I'm not watching that!' No way in hell!" Goodhand exclaimed.
Goodhand considered leaving because the male friend stuck around until about 3AM, but he finally took off and then McDermott and Goodhand ordered room service. The couple reportedly shared a club sandwich and french fries and then actually "just went to sleep" without having sex.
According to Goodhand, she and McDermott snuggled the following morning and McDermott maneuvered getting a later flight back home to Los Angeles.
"It felt cool that I had this connection with this person I didn't really know," Goodhand said.
The couple then parted ways and "neither of us said anything about seeing each other again," she said. "It was, 'Nice to meet you. Crazy that there was this chemistry. I had a great time.'"
Goodhand also told Us she wants to apologize to Spelling for the short-lived affair. In addition to saying she's "sorry" and "f-cked up," she took a lot of responsibility for the weekend's events by saying, "I'm an adult and I make my own decisions."
This isn't the first time McDermott has made headlines for allegedly cheating on Spelling. Tabloids reported in 2012 McDermott had cheated on Spelling with two different women.
Spelling and McDermott met on a movie set in 2005 but both parties were married to other people. After a three-week affair, they left their spouses and wed in May 2006. Because of how their relationship bloomed, Spelling has always feared her husband may cheat on her.
Spelling and McDermott starred in Oxygen's Tori & Dean: Inn Love and Tori & Dean: Home Sweet Hollywood. Spelling also hosted Tori & Dean: sTORIbook Weddings for the network. The couple has a new reality show in the works entitled Tori & Dean: Cabin Fever, which taped this past summer and will air next year on HGTV.