Daisy-Lowe-Matt-Smith-GQ-Man-of-the-Yr-Awards-2011.jpgSay it isn't so! One of our favourite couples, Daisy Lowe and Doctor Who Matt Smith, have reportedly called it quits on their relationship.

The couple are said to have ended their 18-month romance due to work commitments. Tabloids are speculating that the pair also decided to split as Matt had become 'uncomfortable' at the thought of a long-term commitment such as marriage.

"Whenever engagement and marriage was mentioned he was uncomfortable. He's still a young man and the thought of being tied down was a lot to digest," a source told The Sun. "This has come as a surprise to everyone. It was thought they'd be together for a really long time because they were so into each other."

Matt has been busy filming throughout the summer, while Lowe has also been dividing her time between London and LA where she recently posed for Playboy magazine.