Calum came third in this year's series of CBB and has penned a memoir about his life with footballer George, who died in 2004 following a long alcohol addiction.
In the memoir, called Second Best: My Dad And Me, Calum - who adored his father - has written about how George's alcoholism eventually tore his family apart.
Calum grew up in California with his mum Angie and his visits to see George in England became infrequent as his dad's battle with booze spiralled out of control.
A synopsis reads: "His father's fame came at a price, and George's playing career was soon overshadowed by his playboy lifestyle and an increasing dependence on the comforting embrace of alcohol.
"While his tumultuous later years could never diminish the memories of the peerless, often breathtaking, quality of his football, they had a profound effect on Calum."
During his time in the CBB house, Calum opened up about George's death, admitting that Angie had to move to the UK - where he had since moved to - to look after him.
"My mum moved back from the States to here when I was about 27. I was in a bad way," he explained.
Second Best: My Dad And Me is released on 26 March 2015 priced at £16.99