McPhee has been separated from her husband, Nick Cokas, for six months.
Morris' wife, actress Mary McCormack, reportedly kicked him out of the house after he told her the images were about to hit the Internet last week.
"This is a very hard time for her," an insider close to McPhee told the celebrity magazine.
"She's very upset," the source said. "Katharine cares about Michael. But she still cares about Nick too. She didn't mean for anyone to be hurt."