Suprêmes jouissances (aka Belles d'un soir) (1977)
This is one of Brigitte's earliest films, when she was still a brunette. In fact, she has that same lovely auburn hair that we saw in Esclaves sexuelles sur catalogue. Her name appears third among the three female leads -- clearly she is not yet the superstar she'll eventually become, although she's just as stunning.
The film is a typical French farce, with lots of humor, ridiculous situations and clever games. The gals are gorgeous and a pleasure to watch, and the sex is hot when not completely over the top.