CALUM Best had a priceless reaction last night as his mother Angie Best entered the Celebrity Big Brother house - without him knowing.
This year's contestants are split into All Stars, a mixture of past celebrity contestants, and first time celebrity entrants to the house called 'All Stars'.
Calum, who is the son of late Northern Irish footballer George Best, is an All Star contestant in this year's Celebrity Big Brother.
For the first episode of the series, the All Stars were separated from the New Stars and told to act as producers of the programme, initially watching the new contestants enter the house.
Calum, alongside fellow Irish All Star contestant Coleen Nolan, watched as his mother Angie Best entered the house.
Angie Best, a model and former Playboy bunny, was the first wife of George Best with whom she had one son, Calum.
Scroll down to see the moment Calum reacts to his mother entering the CBB house...
"Is that my..?" Calum says, before exclaiming, "Oh my God, that's my mother!"
Viewers loved Calum's surprise to seeing his mother and took to Twitter to praise his priceless reaction.
Angie and Calum Best, who came third in the 2015 series of Celebrity Big Brother, will be the first mother and son duo to feature on Celebrity Big Brother in its history.
— Eleanor ⭐️ (@eleanor_c88) January 3, 2017
Watch Calum Best's hilarious reaction to his mother entering the Celebrity Big Brother house...