Drew: It's hard to act hating Adam
The pair have reteamed for their third romantic comedy - following 1998's The Wedding Singer and 2004's 50 First Dates.
Drew said: "In all seriousness, I was like, 'No one's going to buy that I don't like him. I'm going to be a bad actress, this is awful'."
The pair have great onscreen chemistry and admit they have always got on well from the first time they met.
Adam admitted: "It was hard not to have a good time together."
The 47-year-old actor is dad to two daughters - Sunny, seven, and five-year-old Sadie - and Drew also has two daughters, Frankie, born in April this year and 20-month-old Olive.
The actors admitted being parents drew them to the movie.
"It is all about your kids and that's why we liked the message of this movie," said Drew. "You don't want to go anywhere and do anything without your kids, because life is better with them."
And the 39-year-old actress admitted it wasn't easy to leave Frankie so soon after her birth to promote the movie with friend Adam.
"It's hard to be apart from her. We really didn't plan it this way, but my baby is healthy and happy, which puts my mind at ease because everything is so good.
"I'm just going to take a couple of days to talk about this wonderful movie that is all about family, being a good parent and loving your kids as we all do, and then I'll be right back with her.
"I'm really with family now, so it's a good, healthy environment."
:: Blended is in cinemas now.