In Paris, the pedantic Alexandre lives with his mate Marie in her apartment, an open relationship. Alexandre, who is idle and chauvinist, spends his days reading, drinking and shagging women. After flirting with his former affair, Gilberte, who tells him that she will marry soon her boyfriend, Alexandre meets the Laenne Hospital nurse Veronika Osterwald and they schedule a date. Alexandre learns that Veronika is a promiscuous woman that loves to shag and introduces her to Marie. They have a threesome and Alexandre has a crush on Veronika.