Returning Japanese (1) - S6-E21
Continuity mistake: On the plane whilst Bobby is watching the TV in front of him, you can see a man to the left of Bobby and an empty seat to Bobby's right. The seat arrangement looks to be like the middle row of seats where there is 3 seats instead of two. After the shot shows footage for the "Haiku" movie the shot changes to Bobby and the man sitting next to him but there is now no empty seat next to Bobby. It appears that he is now sitting at a window seat.
Answer: If you are talking about the "Thou shalt not do this, thou shalt not do that" song, I'm not sure if a song like that actually exists. Green Day, the guest voices on the episode, might have just been improvising to keep their appearance from being too obvious.