"He is very mature for his age and is a great guy," a source told ET.
"Everyone in Kate's circle loves Matt and are so supportive of this relationship.
"He was with her in Vegas during this latest leg of her Planet Hollywood Vegas show," Love reported Wednesday.
Another insider said the pair has been spending time together in Miami.
The singer and The romance that remains in very early stages comes after Alex and tech CEO Anne Wojcicki broke up after less than a year of dating.
Beckinsale and her new beau can be seen packing on the PDA in West Hollywood, Calif. The actress rose to fame as the star of the "Underworld" movie series, and will next hit the silver screen in "The Only Living Boy in New York" as a woman who begins romancing her married boyfriend's college-age son.
Kate Beckinsale unearths cringeworthy postcard from Rob Lowe Despite the May-December aspect of Beckinsale's new romance, the pair reportedly has the full support of their inner circle, which makes sense as they met through mutual friends.
Movie theater exhibitors are getting a preview of upcoming blockbusters at Cinema Con, where films like "Fate of the Furious," "Blade Runner 2049" and "Pirates of the Caribbean" wowed the crowds.
Meanwhile, a war of words has been raging among Sean Hannity, Ted Koppel and Bill O'Reilly (and Rep. Jennifer Lopez and recently retired baseball hero Alex Rodriguez are dating, according to reports that have been bubbling up all week.She wore tight black leggings with a black turtleneck sweater with her hair tied up into a messy topknot.The beauty, who accessorized with sunglasses and large hoop earrings, was back on the West Coast after a trip to NYC where she promoted the new season of her NBC drama Shades Of Blue.He really is the sweetest guy and makes her so happy!" Her new relationship comes just two months after she filed for divorce from her husband, Len Wiseman.She is aware, though, that he is a ladies’ man too and is being cautious. She is single and enjoys dating.'The former Yankees third baseman who retired from pro baseball last year shared a picture of himself at the Fox Sports anchor desk.'I’m excited to continue working with the @FOXSports family,' he wrote.