Movie touched raw nerve for tearful Barrymore

Drew Barrymore admits she constantly cried on the set of her new movie 'Blended'.

The 39-year-old actress - who has daughters Olive, 20 months, and Frankie, four weeks, with husband Will Kopelman - plays a single parent in the movie and kept breaking down on set because it reminded her of her relationship with her own mother.

She told Us Weekly magazine: "I couldn't get through my scene with Bella Thorne [Adam Sandler's daughter in the film].

"She needs a mum. I relate.

"Mums are my Achilles' heel, emotionally speaking. I had times in my life when I needed a mum. I'm gonna be there for my kids."

Meanwhile, Drew, who went back to work shortly after giving birth to her second child on April 22, was "too tired" to celebrate Mother's Day in the US on May 11.

She said: "I've been pregnant for three years. On the couch, in sweatpants, eating take-out.

"I was like: 'We should do something special.' But we were just too tired."

The movie marks the third time Drew has worked with Adam, who jokes that he has to give the actress large gaps between movies together or she'd get sick of him.

He said: "She wouldn't want it every day, so I have to give her a pass every four or five years.

"And then I jump in and remind her of why she moved on."