Although he is now legally permitted to consume alcoholic beverages, Lautner drank soda throughout the Saturday night bash, while munching on pizza, slider hamburgers and cupcakes.
"He didn't want people to sing 'Happy Birthday' to him,'" a source told E! News, "but his friends wanted to do it anyway."
"Twilight" leading man Robert Pattinson, Stewart's real-life boyfriend, is in Australia working on the film, "The Rover."
Celebrity Families of 2014 [PHOTOS]
Megan Fox to star in James Franco's 'Zeroville'