A heartwarming video has emerged of a man proposing to his girlfriend in a cinema after expressing his feelings for her through a fake advertisement video.

The footage, shot in Vancouver, WA, USA, captures Adrianna Neil's reaction as she realises the trailer is about her and her boyfriend Ryan Langston.

As the clip finishes, Langston kneels down and hands a ring to Neil who accepts the proposal and jumps in his arms as the crowd cheers.

Man creates trailer to play before the start of the film to propose to his girlfriend. The unsuspecting audience goes wild. Little did she know, her friends and family were hiding among the crowd. After weeks of editing, testing coordination, everything goes off without a hitch.