Morris has been married to actress Mary McCormack for 10 years since they wed in July 2003, and McPhee is also still married to Nick Cokas, 47, whom she tied the knot with in 2008. However, McPhee and Cokas have reportedly actually quietly been separated for at least six months already.
McPhee "has had friends living with her for months," an insider told Us.
"Mary threw Michael out of the house on Sunday night when he told her that TMZ had the photos and that they were about to be released," a source told The New York Post.
The Us insider apparently feels bad for McCormack, whose acting credits have included starring in USA Network's In Plain Sight television series. She and Morris reportedly split their time between Los Angeles and New Mexico, and their three children are all under the age of 10.
McCormack, 45, "is so cool and the nicest person," added the insider. "It's so sad that this happened to her. She's truly great."
A source toldLife & Style that McCormack is "beyond furious and absolutely devastated," and "so is Michael."
"It's incredibly sad. He wants to keep the family together, but as far as Mary is concerned, it's over. There's no going back. Mary only found out this week about the affair after he confessed everything to her," the source explained.
"She had no idea anything had been going on. The last thing she ever thought was that he was seeing another woman... He really wants to make it work between them and try and save the marriage. But at the moment, Mary wants to split up with him."
Morris is reportedly hoping McCormack will forgive him and they can move on from his mistake.
"Only time will tell if Michael and Mary can make things work and get over this," the source added, according to Life & Style. "He loves Mary and is so sorry about what he's done."