Sandra Bullock and Melissa McCarthy, her co-star in new action flick The Heat, shared a ''love story'' when they were filming together.

Speaking to LOOK magazine, Bullock explained how their on-screen relationship played out like a romantic story: ''I think this ended up being a very, very sweet love story. I mean, every movie is a love story, but this one just happens to be amongst friends.''

The 48-year-old actress says that the pair bonded instantly on the set of the movie in which she plays an uptight FBI Special Agent paired with a foul-mouthed Boston cop to take down a ruthless drug lord.

"Our rhythms are different but we worked so well together, they began to click. We made so many connections; every day was heaven. One minute we were taunting each other and the next we were having great fun. It was fireworks because we are really similar.

''We have similar obsessions, like renovating, so we were comparing designing tips. We have mutual friends, so it's the weirdest thing we've never met before.''

Sandra even revealed that their children like to play together, stating: ''My son is three and her youngest is the same age. The kids got along so well from the start. It's been a year since we made this movie and we are still having play dates.''

The Heat hits cinemas on July 31.