Dueling Harmonica

Two individuals, undefined in orientation and/or gender, each partaking of one half of a mans penis, divided lengthwise, by means of oral suction.

After a heated arguement, they decide to compromise and perform the dueling harmonica.

Guy 1: Yo, these two babes shared my donicker last night.
Guy. 2: You mean they gave you a dueling harmonic?
Guy 1: Yeah, I guess.