McPhee and Morris, who met on the set of musical drama "Smash" which was cancelled by US TV channel NBC in May after two low-rated seasons, were photographed locking lips earlier this month.
"This is a very hard time for her. She's very upset," people.com, quoted a source as saying.
"Katharine cares about Michael. But she still cares about Nick too. She didn't mean for anyone to be hurt," the source added.
McPhee, who was married to producer Nick Cokas, has separated from him. Morris is married to actress Mary McCormack with whom he has three daughters.
--IANS (Posted on 30-10-2013)