Prince William asked his wife Kate Middleton to stop flirting during ICAP's Charity Day Wednesday on London’s trading floor, where the two were competing against each other to raise money. William's response came when the Duchess of Cambridge was trying to seal a deal over phone.

"Catherine, I think you can stop flirting with them now!" William said, according to Hello! magazine, after feeling that she was flirting a little with a broker. He later turned to another broker and said: "Sorry my wife is just embarrassing me!"

Middleton and others at the event burst into laughter following the comment. Several employees at ICAP were dressed in costumes and the office space was decorated for the charity event.

The couple also engaged in a game of table tennis, during which William said: "Come on, let's try and have more than a rally. You're not normally this polite when we play."

Middleton, who was wearing a business suit and sported her new hairstyle, reportedly replied to his comment saying: "Or this quiet."

The ICAP is reportedly supporting 13 charities in the U.K. and last year, the event raised 8 million British pounds (over $12 million) globally. This year, the royal couple helped the firm close deals worth $547 million on Charity Day, Us Weekly reported. The money will be given to SkillForce, where William is a patron, and Place2Be and SportsAid, which are supported by Middleton.

The couple has been married for four years and has two children.