Thought I'd jump on Guuzbourg's bandwagon with my favourite French duet of all time:

Another stunning track from the Anna soundtrack. Last year's Gainsbourg DVD release, D'Autres Nouvelles Des Etoiles is a must-own, with the video for this track a standout for me. Extraordinarily beautiful in its simplicity, it features Anna & Serge casually slowdancing whilst gazing into each other's eyes.
And for Roar, the wonderful cover by Bambou and her and Gainsbourg's son Lulu:

Bambou's sensual, breathy vocals, as well as the lyrics seeming more suitable for lovers, does give this a bit of a Nancy & Frank vibe. Nonetheless, it's not much of a stretch to forget that and find it a sweet expression of mother/son closeness (that still sounds a bit off, doesn't it? I give up). A lovely update, tastefully arranged and the type of cover I'm always happy to hear. It does justice to the original, never stomping all over the original feel and thus taking away from it. A fresh take, lovingly executed like this one, can both renew your ears to the finer points you love in the original, and make you glad to hear another version of a favourite.
*Originally mistakenly credited as Anna Karina & Serge Gainsbourg. Jean-Claude Brialy performs the duet with Anna Karina in the film and on the soundtrack, while the version in the video described is performed by Karina and Gainsbourg.
Guuzbourg
Roar
Guuzbourg
Christine
skunkeye
Roar
Guuzbourg
Christine
I love 'Lemon Incest' too, it is the most brilliant bad taste thing ever! Quite a difference though between something that blatant and deliberate, and some of these more puzzling duets that don't seem to know they cross the line.
Roar
Tim
Sadly she looks like Margaret Hamilton now.
Rosa Klebb
Christine
Try searching for it spelt "Charlotte For Ever" +DVD and a few sites come up.