Builder proposes to his unsuspecting girlfriend during an 'escape room' challenge.

This is the heart-warming moment a builder proposes to his unsuspecting girlfriend during an 'escape room' challenge.

Footage of the challenge shows Serena Moden rooting around the room in search of a key and stumbling across an engagement ring.

It was buried with a bottle of champagne and a sign reading 'will you marry me?' inside a filing cabinet.

She turned round to see her partner Gary Heading down on one knee - and CCTV captured the moment she jumped into his arms as she said 'yes'.