I heard this only once but recollect that the following could be as near as Dammit - any knowledgeable corrections gratefully accepted.

RC (at piano): "I'm sad to say I've left my Love in Venice".
RB (not at piano): "...in Venice".
RC: "For a handsome Latin Romeo she fell".
RB: " ...Oh She Fell".
RC: "Now the fickle Bounder's been and gone and left her".
RB: "...and left her".
RC: "Now she languishes beside that Far Canal!".
RB: ".............................................What a Pity!"