I would vote for Raspberries, Strawberries. I have no idea and still don't know what the guys were saying in French. Likewise, when our President gets in front of a mic and starts talking. I have no idea what he's saying or talking about.
Well, as to the French in the song - I recall that in the KT song book that I bought back in the day the lyrics were interrupted at the line in question with the italicized phrase "French double talk".
But far from it, folks. The spoken lyrics of the verses of the original French song are a treat and a bit suggestive, to use an old phrase, and a proper American like Will Holt (the KT's source for this, "Lemon Tree," and "The MTA Song") was just not going to sing them, so Holt apparently came up with the sanitized version that we hear from the KT.
That being said, Dave Guard is attempting to sing the French that Holt himself sang - the full chorus is:
Ah, les fraises et les framboises!
Les vins qu'nous avons bus
Et les belles villageoises
Nous ne les verrons plus
So Guard is singing the first two lines of the chorus, which translate literally as
Ah, the strawberries and the raspberries!
The wines that we drank -
And the lovely village girls -
We won't see them again
Of course, DG is replacing the last two lines with the "La La s" that are not in the original.
Relatively simple French to translate - I had four years of it in high school and another year at Notre Dame, which is after all a French name at a university founded by French priests, so we all had to know a bit of the tongue as a matter of self-defense.
The original song (based IIRC loosely on an older traditional number) has a 1949 copyright by "La Famille Soucy", and I trust that needs no translation. Here's their remastered recording:
Now, as to the longer original -
Sur la route de Longueuil
De Longueuil à Chambly
J’ai rencontré trois belles
Trois belles filles du pays
J’ai fait risette à la jeune
C’était la plus jolie
Elle me clignait de l’oeil
En me disant ceci
...and I'm going to need Mr. Google to translate this because it's a bit more energy than I want to expend on a Sunday afternoon -
On the road to Longueuil
From Longueuil to Chambly
I met three girtls
Three beautiful country girls
I laughed at the young
She was the prettiest
She winked at me
By telling me this
Chorus
Il me clignait de l’oeil
En me disant ceci
Venez, donc cher ami
Y’en a encore a boire
Venez, donc cher ami
Y’en a encore a boire
En faisant la cuillette
Des fraises et des framboises
She winked at me
By telling me this
Come, so dear friend
There's still some to drink
Come, so dear friend
There's still some to drink
While picking
strawberries and raspberries
Chorus
Venez donc vive la joie
Yen a encore à boire
En faisant la cueillette
Des fraises et des framboises
Et nous voilà partis
Dans les champs et les prés
À la fin de l’été
Nous nous sommes mariés
Come and live the joy
You still have to drink
While picking
strawberries and raspberries
And here we go
In fields and meadows
At the end of the summer
We are married
Chorus
I especially like the playful lilt that La Famille Soucy bring to the lyrics.
****Late edit - While I was responding to the authorship question for this song on another site, I discovered that La Famille Soucy is actually from Quebec in Canada and not from France. Who knew? This would make "R&S" likely the only traditional tune that the KT ever recorded from our neighbors in the Great White North.