The Story of... 'I'm Not in Love' by 10cc

10cc's 1975 number one single 'I'm Not in Love' is one of the greatest ballads ever made, and is a solid gold Smooth favourite.

But how was it made? And what was the song about? Who whispered the famous 'big boys don't cry' line?

To celebrate 45 years since it reached number one in the UK, here's the official story behind the song: