The Cake by the Ocean hitmaker has been linked to the Game of Thrones star since early November (16), when they were reportedly spotted kissing while attending a Kings of Leon concert in Rotterdam, Netherlands, on the eve of the MTV Europe Music Awards.
The young couple has since taken its romance to New York City, where Joe and Sophie were photographed leaving a hotel last Wednesday (24Nov16), and on Saturday (26Nov16), they attended a pal's nuptials together in Malibu, California.
Joe's brother Nick Jonas was also invited to the wedding at Calamigos Ranch, where they all pulled silly grins as they posed together in a photo booth to celebrate the occasion.
Nick shared their snaps on Instagram on Sunday (27Nov16) and captioned them, "About last night table 5 madness..."
Joe and Sophie have yet to comment on their new relationship, but it appears the British actress, 20, has already been introduced to the rest of the Jonas family as she joined her new beau on the Jonas family's Thanksgiving holiday (25Nov16) skiing trip to Mammoth Mountain in California.
"Tomorrow everybody flies in together," the singer explained of his Thanksgiving plans on last Wednesday's episode of U.S. morning show Live! With Kelly. "We're going to pick our parents up and go skiing in Mammoth."
Joe did not mention Sophie's vacation involvement at the time, but she made no effort to hide her whereabouts on social media on Saturday, as she posted a picture of herself and a female friend dressed in ski gear at Mammoth Mountain.
Sophie is Joe's latest famous girlfriend - he previously dated Ashley Greene, Demi Lovato, Gigi Hadid, and Taylor Swift, while he was most recently linked to Brazilian model Daiane Sodre in August (16).