Jay (Jason Segel) and Annie (Cameron Diaz) used to love to fuck. Having hooked up in college, they would screw in her dorm, in his car, in the library stacks, even behind a tree. Ten years, two kids and one marriage later, that spark has apparently vanished, prompting the desperate couple to film a comprehensive reenactment of “The Joy of Sex” in a bid to get it back. However, this being 2014, their exploits have been filmed with an iPad and not on a video camera, allowing the file to handily vanish into the little-understood Cloud for storage. As a radio DJ, Jay has an unlikely amount of iPads at his disposal and hands them off to friends and family once he’s done with them, and as a mommy blogger, Annie is dreadfully worried that their three-hour lovemaking session might be seen by anyone they’ve given a device, including her wholesome new employer, Hank (Rob Lowe). To watch Sex Tape is to gloss over the practical hurdles of file-sharing and the leads’ repeated reminders of the Apple tablet’s many merits. To watch it is to reinforce the shameful, fearful mindset with which many Americans regard sex while ignoring the distancing effect technology can have on our everyday lives. Furthermore, to watch it is to endure a constant strain as director Jake Kasdan (Zero Effect; Walk Hard: The Dewey Cox Story) struggles to mine the panicky high-concept premise for three acts’ worth of story, let alone 90 minutes of laughs.