A British couple with two young children decide to get a French au pair because the wife wants to enjoy a more rewarding life outside the house (and the husband wants to enjoy a more rewarding life INSIDE the house). They both get all that they bargained for and more when "Monique" shows up in the shortest of mini-skirts and knee-high go-go boots.
I find British the sex films of this era strangely endearing (and more enjoyable at least than the 16-mm cellulite-and-pimple extravaganzas of low-budget American filmmakers of the era like Harry Novak). Still, they are usually pretty incompetent, and it's not fair really to compare them too much with other films. As British sex films go, this one is most similar to "Baby Love" with Linda Hayden. But while that film was a rather preposterous melodrama, it did show what would no doubt really happen if a stranger moved in and sexually seduced every member of a family; this film, on the other hand, is more of a pure sex fantasy where everything can be papered over with a menage a trois at the end (which the British censors of the day mostly edited out). The lack of any drama here might not be such a problem if there were plenty of sex, but this film is only slightly more racy than "Baby Love" (which had been made a couple years earlier and when its star Hayden was only fifteen).
Rather than being too young like Hayden, the actress here Sybille Kay has the opposite problem--she looks way too old to be an au pair (she looks even older than the couple). She is definitely not unattractive, but she is not a seductive, teasing minx like Hayden. The actress playing the wife, meanwhile, is a pretty nice crumpet herself, which kind of makes you wonder why her husband is so anxious cheat on her.
This is OK but certainly a not a great movie. It's not any more sexy than "Baby Love" and it's A LOT more boring. It's a lot easier to find these days than "Baby Love", but I'd still recommend the latter movie instead which is very similar but much more entertaining.