The Mr Paparazzi founder unveiled his washboard stomach when Doherty questioned him on his "busted out" abs.
Lyons, 46, said: "I had contouring done to my body. I had to get really fit and lose a fair bit of weight. It takes away all the fat around it and actually lets your natural abs be there."
He quipped: "Basically it's the male version of a boob job."
An impressed Doherty branded it the "bees knees", while Lyons described it as the "best thing" he ever did, adding: "I'm over the moon with it."
Celebrity Big Brother continues tonight at 10pm on Channel 5.
> Celebrity Big Brother: Tara Reid turns against Darryn Lyons
> Celebrity Big Brother: Paddy Doherty given phone call to wife on wedding anniversary
Watch Darryn and Paddy speak to Lucien about his feelings for some of the female housemates below:
Watch a video that explains 'ab and pec etching' below: