Possible Clues:

• Shout abuse at a performer
• Awful cheek pinching line, so barrack
• Interrupt (a speaker)
• Give someone a hard time locally with badger
• Give a hard time, in a way
• Razz, as a speaker
• Interrupt (speaker) with abuse
• Sort of cheek that stifles lecturer initially?
• Check letter that glosses over taunt
• Shout 'Ref, are you blind?!,' e.g