Rusty Orchestra
A sexual maneuver in which multiple people (usaully men) engage in oral stimulation of each other whilst offering a reach around, usually on a staircase. The name was coined in relation to the infamous sex act of the Rusty Trombone, as multiple Trombones make up an Orchestra.
"It was pretty awkward when my parents arrived unannounced, they came through the front door to find me tongue deep in the person in front of me, whilst I sat upon the tongue of the person behind. That was the third time this year that my mother had caught me mid Rusty Orchestra."