The Buzz combo is initially when you are fingering a girl and she tosses you off at the same time! A combination of pleasure inflicted on each other! Ending in you both orgasming around the same sort of time in a nice big pleasure (buzz) combo!
Mike: Well i gave her a buzz...
Mike: ....and she buzzed me back ;)
George: Whoaaa thats awesome, you gave her The "Buzz" Combo!