la la lalala la la lalala
the sound you make when you're pretending to be cool but you're actually a total mess
She was doing 'la la lalala' in the hallway like she was in a music video and tripped over her own shoelaces
He said 'la la lalala' during a group project because he had no idea what the question was
I did 'la la lalala' in class because I couldn't answer the math problem and I was too scared to say I didn't know