B1A4 has been followed by the nickname, 'paper idols', ever since their debut, and it seems they still have a hard time shaking off that nickname as actor Lee Sung Jae also thought they were some sort of paper!

During a recent filming for 'I Live Alone', Lee Sung Jae brought laughs as he demonstrated that he remains in the dark about the latest idol news, even though his two daughters are big fans of idol groups.

While chatting with his two daughters living in Canada on the phone, they landed on the subject of idols.

Lee Sung Jae's daughter revealed herself to be a fangirl mentioning, "I like B1A4". After taking time to process this piece of information and not understanding what his daughter meant, Lee Sung Jae asked, "B1A4? Isn't that copy paper?" (A4 paper is widely used in Korea).

Although the actor tried to redeem himself by mentioning SHINee, an idol group name he knows, he kept saying 'Tee' instead of Key, once again unintentionally bringing laughs on the filming set with his lack of idol knowledge.