Money Saving Expert Martin Lewis was teased by Holly Willoughby and Philip Schofield when he made an embarrassing mistake on This Morning.
The financial guru pretended to walk off set after he got something wrong live on air.
He was taking a call from a member of the public who asked him about the best bank cards to take abroad.
Caller Cath was worried about extra charges and asked if she should change her bank, Liverpool Echo reports.
"Your card is either, Lloyds, Halifax, TSB, Santander and if it is not one of those it is Natwest or RBS," Martin said while trying to guess her bank.
The caller said: "No, it's HSBC."
Presenters Holly Willoughby and Phillip Schofield started laughing, with Holly shouting "Oh, no!" and Phil adding: "Big gamble."
Martin, 47, then got up and went to walk off set, pretending to be in a mood.
Holly and Phil teased him about getting it wrong, and he said: "I didn't get it wrong, I just guessed."
Viewers thought the exchange was hilarious, with some shocked to see the expert get something wrong.
One said: "Martin Lewis: "let me guess, your card is either... *lists every bank possible*"
Another said: "Smug Lewis...gave out every possible bank name but the correct one."
A third said: "LOOOOOOOOOOOOOOOOL Name 5 still get it wrong lol"
And a fourth added: "Martin Lewis basically named all the bank cards."
*This Morning is on ITV1, weekdays and Sundays from 10:30am
