A couple of things.

Olivia de Havilland won a Best Actress Oscar, I believe, for her
lead role performance in the Hollywood film
The Heiress,
based on Henry James's Washington Square.

The false-hearted lover was played by Montgomery Clift,
and he sits at the piano and sings this very song.
First he sings it in French -- I'll come back to that in a moment.
Then he talks his way through an English translation
while still playing the piano.


Now, the original-language chorus in 'Plaisir d'Amour.'
Whoever did the film's musical direction,
and coached Montgomery Clift on how to sing the French,
made this interesting adjustment to that final line in the chorus,
about which Joe Offer voiced his doubts several posts back.

Yes, the conventional way the words fit the melody is:

"Cha-grin d'a-mour du - re tou- te la vie - ie - e."

In The Heiress:

"Cha - grin d'a - mour du - re tout' la vi', tout' la vi'."
With a single syllable for each note of the melody.