Sept. 22, 2011 -- intro: "Mad Men" star January Jones welcomed her first child last week, a baby boy, but we're no closer to learning who the father of the baby is.
Jones gave birth to son Xander Dane Jones Sept. 13, her rep confirmed to People.
That explains her absence from Sunday's Emmy Awards, where "Mad Men" picked up a fourth award for best drama.
But it's the drama surrounding her son's father that has tongues wagging.
"I think you can allow people to know as much as you want them to know," her co-star, Elizabeth Moss, told E! online. "And I've seen many people do it very successfully. ... Some people don't mind and some people mind."
Jones seems to fall into the second camp, but that doesn't stop us from listing who the prime suspects for her mystery baby daddy might be. Click through to see the top five.
quicklist: 1category: title: Matthew Vaughnurl: text:
E! Online first reported that Matthew Vaughn, the director of Jones' most recent film, "X-Men: First Class," had a "very close" relationship with the actress on set.
Vaughn, who is married to former supermodel Claudia Schiffer, strongly denied any affair.
Still, he remains a prime suspect after he "abruptly" left town, according to E!, around the same time Jones made her surprise announcement in April that she was expecting.
He also skipped a screening of the film, claiming "severe" tonsillitis, although E! claimed he was talkative during "X-Men" interviews earlier that day.
quicklist: 2category: title: Jason Sudeikisurl: text:
Jones was most recently linked to "SNL" actor Jason Sudeikis, although he claims not to be the father.
A tongue-tied Sudeikis told a Washington Post reporter when asked at the White House Correspondents Dinner whether he had any comment about Jones' baby bump: "I'd rather -- yes but no."
When the reporter asked Sudeikis if he was surprised to find out Jones was pregnant, he stammered, "No, I -- no, I didn't have anything [else to say]."
quicklist: 3category: title: Michael Fassbenderurl: text:
Jones was still filming "X-Men: First Class" at the beginning of the year, leading many to suspect that her baby daddy was one of her famous co-stars.
The man most in contention was Michael Fassbender, the German-born Irish actor best known for his role in Quentin Tarantino's "Inglourious Basterds."
Even though Fassbender reportedly began dating another "X-Men" co-star, Zoe Kravitz, that hasn't stopped some gossip websites from speculating that Kravitz is just a cover to take the heat off Fassbender as a possible baby daddy for Jones.
quicklist: 4category: title: Bobby Flayurl: text:
Sure, grillmaster Bobby Flay seems like a long shot to be Jones' baby daddy.
Then again it was odd when Flay was the person Jones called for help after she crashed her Range Rover into several parked cars in June. For one thing, Flay is married to actress Stephanie March.
Flay's publicist, Jennifer Baum, said he was watching the Lakers-Celtics game with Jones and a group of friends earlier in the evening at the London West Hollywood Hotel. Although they had met only once before -- when Jones gave Flay her number because she wanted to remodel her kitchen -- she called on Flay for help after the crash.
Baum said Flay went to the scene to check on her.
quicklist: 5category: title: Xander Berkeleyurl: text:
This one seems way to obvious.
Married actor Xander Berkeley did the film "Seeking Justice" with Jones last year, but it seems unlikely she would name her baby after Berkeley if she were trying to keep an affair between them secret.
Then again, stranger things have happened in Hollywood.