January Jones Shows Off New Son On 'Mad Men' Set

33-year-old Mad Men starlethttp://www.people.com/people/article/0,,20536243,00.htmldidn't waste anytime in showing off her new son to her co-stars. 

Jones brought along her 4-week-old son, Xander Dane Jones, to the set of her AMC drama on Tuesday. Made Men recently began filming it's 5th season after being on hiatus for a year and is set to premiere in 2012. I cant wait for it to return!

Also...she's still keeping quiet on who the babies father is.

Below are some photos of Jones on the Mad Men set a few days ago.