"Mad Men" star January Jones is remaining tightlipped when it comes to the identity of her son's father.
The 35-year-old actress was asked about it during a recent interview with the New York Times, but January refused to share any details on the father of her 20-month-old son.
"That's my son's business," she said. "It's not the public's business."
In the article, the NYT questioned if former co-star Michael Fassbender or her "X-Men: First Class" director Matthew Vaughn was Xander's father.
The actress explained that she often thinks of a fellow Hollywood star's advice when it comes to deciding what to divulge.
"Jack Nicholson once told me, 'You should never give your personal life away, otherwise people will pick you apart. They'll never believe in your character,'" she said.
But she also teased that questions surrounding her son and her personal life could he answered one day. "Women should have lots of secrets," she continued. "It's our right to have secrets. Otherwise, what would we write in our memoirs?"
Copyright 2013 by NBC Universal, Inc. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.