Super Junior's Ryeowook didn't have Leeteuk's phone number until recently!

On the October 12th episode of 'Knowing Brothers', Leeteuk shared, "Ryewook is not in our message chat room. One day, I left a birthday message for Ryeowook, and there wasn't a response for 30 minutes. I then found out Ryewook wasn't in our chat room."

Ryeowook then said, "I was sad because none of the members congratulated me on my birthday," and the members surprised the 'Knowing Brothers' after saying that Ryeowook didn't have Leeteuk's phone number until recently.   

Leeteuk explained, "My phone number changed during the time Ryewook was serving in the military," and Ryeowook added, "Leeteuk hyung didn't know my number, and I changed my number and didn't tell him."

In related news, Super Junior are returning with "SUPER Clap" on October 14 KST!