“Spring Awakening” star Skylar Astin and “Twilight” thesp Justin Chon are in early negotiations to join Miles Teller in toplining Relativity Media and Mandeville Films’ comedy “21 and Over.”“The Hangover” scribes Jon Lucas and Scott Moore are writing and directing the pic, which follows two childhood friends who drag their straight-arrow buddy out to celebrate his 21st birthday the night before an all-important med school interview. As one beer leads to another, the evening spirals into an epic misadventure of debauchery and mayhem. Astin and Teller will play the hard-partying pals, while Chon will play their perpetually anxious friend. Mandeville principals Todd Lieberman and David Hoberman are producing the film, which is slated to start production later this summer. Chon is best known for playing Kristen Stewart’s geeky classmate Eric Yorkie in Summit’s “Twilight” franchise. He recently wrapped “Breaking Dawn – Part 1″ and next stars alongside Tom Felton and Taraji P. Henson in the golf-themed indie “From the Rough.” While Astin previously appeared on the bigscreen in “Hamlet 2″ and “Taking Woodstock,” he’s best known for playing Georg in the Tony award-winning musical “Spring Awakening.” Astin is repped by UTA and Principal Entertainment, while Abrams Artists Agency and Luber Roklin Entertainment rep Chon.