The baby daddy drama continues!

January Jones has kept the identity of her baby's daddy a secret since announcing her pregnancy in late April.

She gave birth September 13, and new court docs show that she still hasn't named her baby's daddy -- son Xander Dane Jones has no name listed under "father" on his birth certificate! The space is blank!

So what's with all the secrecy?

Speculation ran rampant when January first came forward with her pregnancy news that the baby daddy was X-Men: First Class director Matthew Vaughn ... and that January had to keep it a secret because Matthew, 40, is married to supermodel Claudia Schiffer, 41.

Jones and Vaughn supposedly became close while on the set of X-Men.

SNL funnyman Jason Sudeikis, who January dated earlier this year, was also rumored to be the pop, but he denied it.

So Xander ... who's your daddy?!?

Miley Cyrus and beau Liam Hemsworth were a hands-on couple on Saturday ... and Liam paid one part of Miley's bod some special attention!

Hemsworth gave Miley, who wore a weather-appropriate maxi dress, a loving grab on the behind as the couple headed to Iwata Sushi in Sherman Oaks.

But, every couple has their arguments! The two got in a squabble while out -- see pics of the fight after the jump!

Lady Gaga performed at the iHeartRadio Music Festival at the MGM Grand in Las Vegas Saturday night, and took a moment to put a serious spin on the superstar fest.

Gaga dedicated her performance of "Hair" to Jamey Rodemeyer, a 14-year-old fan who committed suicide last week. Rodemeyer Tweeted Gaga thanks for her positive inspiration before he killed himself. Said Gaga at the fest:

"We lost a little monster this week, and I wanted to dedicate this song to him tonight because he was really young. ... I know it's a bit of a downer, but sometimes the right thing is more important than the music, isn't it? Let's do this one for Jamey."

Gaga has vowed to meet with President Obama over Jamey's suicide; she says it is one too many that has come as the result of bullying. Mother Monster wants to make bullying a hate crime.

Kelly Osbourne and her dog were a cute couple as they walked the streets of Beverly Hills on Saturday!

Kelly, ever the fashionista, even seemed to color-coordinate her black outfit with her pup's black fur.

Osbourne was out in search of a new phone, which she got on Saturday. And it seems she had a busy day running errands! Saturday night she Tweeted, "only my dad would text me at 11pm to go get him some 'strong coffee beans' ... where ... do i get strong coffee beans at 11pm! & why????"

On Sunday, Kelly, mom Sharon and dad Ozzy were heading to her Uncle Tony's wedding. Congrats!

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Bruno Mars started off the iHeartRadio Music Festival in Las Vegas at The Bank Nightclub and GOLD Boutique Nightclub & Lounge on Friday night!

The seven-time Grammy nominee performed at The Bank at Bellagio Resort & Casino, where the crowd, which included Glee's Naya Rivera and Darren Criss, sang along to "Grenade" and "The Lazy Song."

Mars and pals partied until 3 a.m., then headed back their VIP suite.

Selma Blair is all about son Arthur, and we don't blame her! He's too cute!

Blair and fam hit up a friend's birthday party in LA on Saturday, where Selma found all sorts of ways to show love to her baby boy -- including wearing a fake mustache! Adorable!

She may be a troublemaker, but when she looks this good on the red carpet at an AIDS fundraiser, we're pretty much willing to forget about all of her bad behavior!

On Friday evening Lindsay Lohan attended the amfAR Milano 2011 benefit gala at La Permanente in Milan, Italy, and the 25-year-old starlet rubbed shoulders with event co-chairs Heidi Klum and Bar Refaeli, along with famous faces like John Legend and Camila Alves.

On Saturday Lindsay attended the Philipp Plein Spring/Summer 2012 show in Milan, and it was just announced that she'll be the face of his Spring ad campaign. “Lindsay is a beautiful, highly acclaimed actress and model," Philipp gushed at the show. "We will be able to create unique images: Refined and luxurious, but also full of sensuality.”



Talk about a delicious duo!

Kat Von D and Jesse James have called it quits ... again.

"I am not in a relationship," Kat wrote on her Facebook page. "And I apologize for all the 'back and forth' if it's caused any confusion." A source also confirms the split to People mag, and though her former fiance hasn't commented on the break up, we're guessing it's only a matter of time before he shares his side of the story.

The couple previously called off their engagement last July, but less than a month later they decided to give it another shot. When the two got back together, Jesse said, "Sometimes you are only given one chance in life, I will never stop fighting and striving to hold on to her."

That sounds sweet and all, but now we're beginning to wonder if his wandering eye had something to do with their latest split. Kat tweeted yesterday, "As much as I dislike being wrong, I must admit this time I was. #noregrets." Think he cheated on her like he did with ex-wife Sandra Bullock?