'Sex Tape' Is One Of Cameron Diaz's Worst-Opening Movies Ever

It was not a good weekend for Cameron Diaz at the box office.

Her new movie "Sex Tape" with Jason Segel made $15 million over the course of three days.

The Sony Pictures comedy about a married couple's sex tape getting shared over Apple's iCloud with friends and family cost an estimated $40 million to make.

It's one of Diaz's worst-performing opening weekends to date. Her last movie, "The Other Woman," with Leslie Mann and Kate Upton debuted to $24.7 million in April.

Overall, the film came in fourth this weekend at the box office behind new sequels "The Purge: Anarchy" ($28.4 million) and Disney's "Planes: Fire and Rescue" ($18 million).

"Dawn of the Planet of the Apes" dominated for the second weekend in a row scoring $36 million. The film has now made $240.5 million worldwide and has helped Fox become the first studio this year to hit $1 billion at theaters.