Well I ain't no Frenchman, ain't no Frenchman's son, but I can phonetically write the way I hear it in my head in pidgin french:

Plasir d'amour, ne dure q'un moment
Chagran d'amour dure tu
la vie

Joys of love are but a moment's time
the pain of loving you lasts the whole life through
.

But I'm sure you can easily find it with correct spelling.

Mark