'Sex Tape': Does it make the grade?

Once upon a time in college, Jay (Jason Segal) and Annie (Cameron Diaz) met and fell in love and went at it like proverbial rabbits.
They did it in the car. They did it in the quad. They did it until they shook the books out of the library stacks.
Then Annie got pregnant and a decade went by and they became busy, harried L.A. parents with carpools and deadlines and no time for the randy gymnastics of their youth. The spark isn't gone, but it's definitely dimmed. ''How the hell do you get it back?'' Annie, now a mommy blogger with a pending book contract, asks her readers.

Which goes great until Jay accidentally uploads the result to every iPad he's ever given away to friends and neighbors and the Rasputin-bearded mailman, and can't digitally retrieve it (''It went up to the cloud...Nobody understands the cloud! It's a f*****g mystery!''), leaving them no choice but to go out and physically wipe or steal or smash each one.Because this movie is called "Sex Tape" and not "A Nice Spa Weekend in Napa," you can probably guess the answer: With the help of some old roller skates, a bottle of tequila, and a vintage copy of "The Joy of Sex," Annie and Jay decide to make their own home movie.
That's when "Sex Tape" becomes a caper not unlike "Horrible Bosses" or "We're the Millers" or [insert another Jason Sudeikis movie of your choice here]. It's clumsy and wacky and intermittently amusing, and Rob Lowe looks like he's having a great time playing Real-Life Ned Flanders With a Deeply Weird Side once again. (Jack Black's uncredited bit as an Internet porn magnate is less fun).
Director Jake Kasdan, who also helmed "Bad Teacher" and "Friends With Kids," doesn't quite seem to know what tone he's going for, and the last half of the movie veers wildly between crude hard-R comedy and warm-hearted teachable moments.
Blessedly, it's also short; roughly half the running time of the three hours Annie and Jay clock in their much-vaunted sexcapades. So everybody gets their happy ending.