Martin Kemp and Shirlie Kemp were unveiled on Saturday night as the singers behind the Cat and Mouse disguises, shocking their radio DJ son.
Read more: The best Masked Singer guesses so far
In a video posted on Twitter, Roman loudly exclaims "shut the f*** up" when the reveal happens before declaring "I knew it" and yelling at giggling mum Shirlie that she's a "liar".
In another tweet, Roman said he "cannot undo" the embarrassment of shouting the words "take it off" at his parents on TV.
Warning: Video contains swearing
When the former Spandau Ballet singer and his wife — one half of the duo Pepsi & Shirlie — were unmasked, they revealed that Roman had no idea they were taking part.
"Most people say they are doing it for their kids," Shirlie joked on stage, before Martin added: "We’re doing it to embarrass them".
Shirlie later tweeted that Roman and his sister had been told that their parents were "on a romantic getaway" during the time they were filming their performances for the show.
The panel of judges had not managed to guess the identity of the Kemps either, with suggestions including David Walliams and Amanda Holden or Line of Duty stars Martin Compston and Vicky McClure.
Cat and Mouse took to the stage for the last time on Saturday night, having been beaten by fellow contestants Jellyfish, Knitting, Otter and Phoenix.
Knitting saved themselves in the final sing-off by performing Memory from the musical Cats, which led judge Rita Ora to suggest stage legend Elaine Paige might be behind the costume.
Cat and Mouse — the first duo in the UK show's history — became the third costume to be unmasked, following Chris Kamara as Ghost and Lulu as Piece of Cake.
The Masked Singer will return on 21 January, with the five singers who did not perform this week taking to the stage in an attempt to avoid elimination and keep their mask on.
Watch: Costumes revealed for The Masked Singer 2023