updated 01/08/2013 AT 2:00 PM ET
•originally published 01/09/2013 AT 8:00 AM ET
Devoted son, quirky leading man – and everyone’s favorite fantasy boyfriend.
The “hey girl” Internet obsession, 32, “is an incredibly sweet boyfriend,” a Gosling source tells PEOPLE in this week’s cover story. He and Mendes, 37, “get along so well because she’s not needy or smothering,” says another insider. “They just work.”
Mendes is hardly the only one to fall under Gosling’s spell. The former Mouseketeer – who brought his mom, Donna, as his date to the Jan. 7 Gangster Squad premiere in L.A. – is “funny and charming,” says the film’s director, Ruben Fleischer.