Je T'aime...Moi Non Plus from Jane Birkin et Serge Gainsbourg
From the YouTube description:
In 1968 Gainsbourg had written "Je t'aime, moi non plus", an explicitly erotic song which he had recorded with Brigitte Bardot. After the pair's relationship had ended, Bardot begged Gainsbourg not to release the recording as a single and Gainsbourg, the perfect gentleman, respected her wishes. However, in 1969 Jane recorded the notorious song as a duet with Gainsbourg and it appeared on the pair's joint album "Jane Birkin et Serge Gainsbourg".
When "Je t'aime moi non plus" was released as a single later that year it caused an absolute scandal. Indeed, Gainsbourg's erotic lyrics and Jane's passionate whispering totally outraged public opinion. The international press attacked the song's "lewd" message, radios banned it from their playlists and the Vatican went so far as to issue a statement condemning the immoral nature of the song. In short, "Je t'aime moi non plus" benefited from a huge amount of free publicity and rocketed straight to the top of the charts, selling around a million copies in the space of just a few months. Needless to say, Gainsbourg and Birkin became the most scandalous couple of the year and their relationship became the subject of intense media scrutiny.