The former Celebrity Love Island contestant can be seen putting his manhood inside a large football sock as he poses with his pal Wayne Linker.
Standing shirtless, Calum flaunted his gym-honed physique as he dropped his Calvin Klein boxers to his knees.
Meanwhile, Gary Lineker’s brother pulled the same pose.
Wayne captioned the post: “Throwback to the c*** in a sock charity campaign…”
Seeing the upload, Cal quickly replied with a string of laughing emojis before adding: “For f*** sake mate!”
Meanwhile, DJ Tom Zanetti joked: “Haha can of coke and baby’s arm.”
As the post picked up more than 5,000 likes, many fans jumped into the comments section to express their delight.
One fan wrote: “Haha sexy lads.”
Another added: “I think I just died.”
However, a third was less convinced, replying: “I’m not sure what I feel about this…”
The shot was taken in 2014 when Cancer Research UK aimed to repeat the success of their no makeup selfie campaign.
In just 48 hours, the breast cancer campaign raked in a staggering $3.3million.
