By Kat Giantis
If Christina Aguilera hoped to keep romance rumors to a minimum while dining out with pals Nicole Richie and Joel Madden on Friday night, she should have planned her paparazzi-thwarting moves a little more carefully.
As the group drove away from Los Angeles hot spot SoHo House with Madden behind the wheel, paparazzi snapped a blanket-covered "mystery man" hiding in the backseat with the chanteuse, 29, who split from husband Jordan Bratman last month.
So, who's the camera-shy fella?
Sources identify him as Matthew D. Rutler, a guitarist and set assistant on Aguilera's soon-to-be-released flick "Burlesque." Word is, the peroxide-topped popster has been seeing Rutler since shortly after her marital meltdown.
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"It's not serious yet, but it's something she is exploring and finding comfort in," a source tells People magazine. "It's new and she's taking it day by day."
Continues the insider, "She and Jordan were having problems for a long time. What kept them together is their love for their son [Max, 22 months]. She met [Matthew] on set and, during a difficult time, leaned on [him] as a friend. After she and Jordan separated, the friendship turned romantic."
Another confidant echoes the casual-dating scenario to Us, explaining, "They've been on a few dates over the last few weeks. It's not serious. She's not looking to jump into a relationship right now. She has a lot going on with the movie and is focusing on spending as much time as possible with Max."
That said, "He's been really good for her," opines the spy, "and is helping her through this difficult time."
RELATED: Xtina: 'Women are stronger than men'
Or is he? "I can tell you that they are absolutely not dating," Rutler's New Jersey-based mom, Kathleen, insists to RadarOnline. "They are friends but nothing more than that."
She says Aguilera "needs a shoulder to cry on and an ear to listen to her problems, and that is exactly what Matthew is doing ... she really finds it hard to find anyone genuine to listen to her."
The reason Rutler ducked from the shutterbugs is because "he isn't into stars and all that Hollywood glamour," says his mom. "His band and his work is his focus right now."
Initial reports claimed the fourth member of the double date was Joel's twin brother, Benji, who was linked to Xtina shortly after her breakup. Insiders, however, have adamantly denied the hookup chatter (also denied: those Samantha Ronson rumblings).
Aguilera has dropped hints about her desire to move on after her five-year marriage to Bratman.
While performing at a Halloween gig in San Diego, she reportedly told the crowd, "In light of my current situation, here's to finding new love."
What do you think of Christina's seemingly quick rebound? Tell us in the comments.