01/04/2007 at 03:00 PM EST
Who was the lucky lady on Justin Timberlake's arm at Wednesday's Hollywood premiere
of his new movie Alpha Dog
? His mom, Lynn Harless.
There was no sign of Timberlake's longtime girlfriend, Cameron Diaz, at the premiere or afterparties – but Harless, 45, proved perfectly capable of keeping up with her 25-year-old son.
After the movie, in which Timberlake plays a member of a drug dealer's gang, mother and son hit the afterparty at Ivar Studios, where at one point Timberlake obliged a group of female fans by posing for a picture with them ("All of a sudden, I feel cheap," he joked).
He and Harless hung out in the venue's VIP section, chatting and taking photos with his Alpha Dog
costars until just before 11 p.m., when they headed out to the club Social Hollywood.
There, they met up with a jeans-and-tank top-clad Scarlett Johansson, who recently filmed a video for one of Timberlake's new songs. She shared a one-on-one with him for about an hour before Harless joined in the conversation – and then hit the dance floor with her son to the Jackson 5's "ABC."
Later, while Timberlake hung out with some of his Alpha Dog
costars, including Emile Hirsch, Shawn Hatosy, Ben Foster and Olivia Wilde, Harless and Johansson talked until the club closed at 2 a.m., when Timberlake and his mother took off through the private back exit.