Adult actors are clamoring to be cast in Lena Dunham’s new season of “Girls,” which premiered last night, we hear. “Django Unchained” star Dennis Christopher told us he’d just been to an NYC premiere with his pal Debbie Harry, and joked that every actor who’s 50 is salivating over potential parental roles for Zosia Mamet, Allison Williams and Jemima Kirke. (Be careful what you wish for! Based on last season’s appearance of Peter Scolari as Dunham’s dad, the parts could contain some bizarre sex and nudity.) Rita Wilson pops up on the HBO series as Williams’ (fully clothed, so far) single mom this season. Christopher starred in the classics “Breaking Away” and “Chariots of Fire,” and plays Leonardo DiCaprio’s unctuous Southern lawyer in “Django.”