"He told me he and Tori had a sexless marriage," 28-year-old Emily Goodhand told Us Weekly, adding that she spent two nights with him at the Fairmont Royal York Hotel.
McDermott, 47, has been married to Spelling, 50, for the past seven years. The couple has four children together: Liam, 6, Stella, 5, Hattie, 2, and Finn, 16 months.
Last October, the former 90210 star told People magazine she and her husband were facing finical troubles and her current life is nothing like it was back when she starred on the hit TV show.
"I haven't bought a purse in three years. And it's fine. I look back on that girl who shopped at Gucci in my 20s, and I can't even relate," she said at the time.
More details from McDermott's alleged affair will be featured in the new issue of Us Weekly, out Thursday.