The Game Of Thrones star has been linked to Joe 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.
Last month (Nov16), Joe invited Sophie to join his family for a skiing trip to Mammoth Mountain, California over the American Thanksgiving holiday, and now he has travelled to the U.K. to meet her relatives.
The DNCE frontman was seen in North London on Monday (05Dec16), when he enjoyed a traditional pub lunch at The Stag with Sophie and her loved ones.
Photos published on DailyMail.co.uk show the group taking a stroll after its meal, with Sophie's mum Sally smiling as she chatted to Joe.
The 27-year-old pop star dressed casually for the Turner family outing, wearing ripped black jeans with a grey T-shirt paying homage to David Bowie, and covering up with a maroon suede sports jacket under a khaki overcoat.
Sophie, meanwhile, braved the winter chill by donning a black crop top and blue jeans with a black bomber jacket and heeled boots, as the 20-year-old openly kissed and cuddled with her new man.
The young couple has been spending a lot of time together in recent weeks, with Joe taking Sophie as his date to a friend's wedding in Malibu, California after Thanksgiving break, when they were also joined by the singer's younger brother, Nick.
The stars have yet to comment on their blossoming romance, but 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).