Jenna Elfman, a serious Scientologist, may have gotten a bit of a jolt last night during the premiere of “Friends with Benefits.” Elfman is in the movie–she plays Justin Timberlake’s sister. But she’s not in a scene in which Justin and Mila Kunis hike up to the Hollywood sign in L.A. and get arrested for trespassing. It’s there that JT makes a quippy joke about Scientology–calling it “great science fiction.” Ouch! The joke gets big laughs and is very pointed. This may have accounted for Elfman not showing up after the screening at the Top of the Standard (aka the Boom Boom Room) for the movie’s party. Here’s what she missed: Timberlake in a section cordoned off by his huge and unfriendly personal bodyguard so the singer-turned-actor would be guaranteed no contact with any of the invited guests. Emma Stone — who’s great in this month’s other comedy, “Crazy Stupid Love”–and Mila Kunis joined him. Elsewhere in the club we ran into Courtney Love, Penn Badgley (about to start shooting a movie about late singer Jeff Buckley) with gf Zoe Kravitz, CAA chief Kevin Huvane, Patricia Clarkson with her nephew and his girlfriend, and New York socialite Patricia Duff, who runs The Common Good organization.