Something along these lines was overheard this morning.
ATC: 'Virginxxx fly heading 090 degrees'
Virginxxx: 'Heading 090 degrees, Virginxxx'
ATC: 'Batman118 descend FL180'
Batman118: 'Descend FL180, Batman118'
Unknown voice: 'Batman?!'
Unknown voice: 'Nanananana'
Unknown voice: 'Where's Robin?'
Unknown voice: 'And Catwoman?!'
Unknown voice: 'She's sat next to me!'
Unknown voice: 'What kinda callsign is that?!'
Batman118: 'Just because you're jealous...'
Made me chuckle