Selena Gomez had a ball at a Sundance Film Festival party, partially thanks to a mysterious friend to whom Gomez seemed to take a strong liking. Now, Gomez fans are wondering about the identity of her new friend.

Gomez was seen spending a lot of time with an unknown man during a party celebrating her upcoming Sundance film, Rudderless,

One witness told PEOPLE that Gomez had her eyes on this man from the beginning.

"She went right up to him really early on in the evening," the source said.

According to E! News sources, the man was probably just one of Gomez's friends. The sources insist that the 21-year-old is single.

Still, an E! News "eyewitness" said that Gomez and the unnamed man were close for the entire night.

"He didn't leave her side," the eyewitness said. "The pair hung out in a corner. Selena was in good spirits and was seen dancing to music as he watched her admirably."

Gomez was not the only one having fun at the party. Rudderless co-star Billy Crudup was also at the party, and director William H. Macy even took a turn at the mic, singing "I'm an A-hole." According to E! News, the crowd loved it and was laughing and dancing to his tune.

Check out Gomez enjoy the party in the video below:

Recently, Radar Online reported that Gomez had a fight with her ex-boyfriend, Justin Bieber, 19, via text message.

"U r a drug addict. U need help," the text message allegedly said. "Stop. You need to listen to Scoot [Braun, Bieber's manager] and go to rehab. U r sick."

According to Mail Online, however, Jill Fritzo, Gomez's representative, said the texts are "not real."

"U need to grow the f**k up. I hope you get jail time," another text message claimed to be written by Gomez said. "U deserve it at this point.'"

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