On the October 28th episode of 'Knowing Brothers', Heechul bragged that he's a big reader, and Kang Ho Dong couldn't help but shut him down, saying, "You don't read books. That's why you don't have a girlfriend."
Heechul responded, "Is that true?" and Kang Ho Dong joked roughly, "It's because your brain is completely empty."
The Super Junior member then commented, "It seems like you're being honest, and I don't know what to say so it's even more annoying."