"Sophie and Joe met through mutual friends," a source tells ET. "They have been dating for a couple of months. They spent Thanksgiving together in Mammoth Lake. They are really into each other and having a great time."
Following the release of photos showing the pair getting cozy at a Kings of Leon concert in Rotterdam, Netherlands, on Nov. 5, the two appeared even closer at a friend's wedding in Malibu, California, on Nov. 26.
The 27-year-old singer and the 20-year-old actress were adorably goofy while posing for group pics in an old-school photo booth, along with several others. The new couple beamed as they huddled together, one row behind Joe's younger brother, Nick.