Justin Timberlake & Mila Kunis: 'They're Friends,' Source Says

Although "pretty inseparable" on SAG night, the source denies trouble with Jessica Biel

Photo: Ron Wolfson/Landov

It was hard to miss: Justin Timberlake and Mila Kunis spent much of the night after the Screen Actors Guild Awards hanging out together at the PEOPLE/Entertainment Industry Foundation SAG Gala.

Then later on Sunday night, the singer/actor and his Friends With Benefits costar were “pretty inseparable” at another bash thrown by the Weinstein Company and Dewars, an observer says.

But a source insists “they’re friends” – period.

As for Timberlake’s girlfriend, Jessica Biel, the actress rarely walks a red carpet with Timberlake. But despite their lack of PDA, “Justin and Jessica are definitely together,” says the source. “They’re happy in their relationship.”