Justin Timberlake was so concerned about Britney Spears, who entered rehab in February, that he reached out to her, he has revealed.
"I called her because I worried about her," Timberlake, 26, said recently at a press day for his new movie Shrek The Third.
But Spears, who checked out of Malibu's Promises treatment center in March after nearly a month, is on the right track, Timberlake said.
"She's a great woman. I'm rooting for her," he said. "[It] seems like she's getting everything under control now."
Timberlake, who in January split with Cameron Diaz (his costar in Shrek, who also attended the press day), said being single has its ups and downs.
"The advantages are that you don't get in as many arguments, and the disadvantage is that you're talking to yourself," he said.
But he isn't exactly lonely. Timberlake spent time with Jessica Biel, 25, at a barbecue party at his L.A. house last week, PEOPLE reports in its new issue.
Things between the pair got "hot and heavy," says a source in the singer's circle.
This isn't the first time Timberlake and Biel have been spotted together: In January they went snowboarding with a group of friends in Park City, Utah, and hung out backstage at one of Timberlake's concerts in San Diego.
And at Prince's Golden Globes party that month, Timberlake and Diaz had a spat after Diaz saw Timberlake chatting with Biel.
As for Biel, when it comes to Timberlake, a source tells PEOPLE the actress is "crazy about him."