Director Nello Rossati is perhaps most famous (well, outside Italy anyway) for a film called "The Sensuous Nurse", which featured original Bond girl Ursula Andress and played on late-night cable in America in the 80's. Perhaps as a result that film got a very decent DVD release (with subtitles even) a few years back. This film is pretty similar to that one; however, it has met a very different fate--the French got ahold of it at some point, dubbed it into French, and added about twenty minutes of hardcore porn inserts! The plot (which between the French dubbing and random XXX footage was pretty hard for me to follow) involves a typical bourgeois Italian patriarch, his unfaithful wife, his shy, virginal son and his saucy, voluptuous maid (Orchidea DeSantis)--all elements of "The Sensuous Nurse" as well--but there's also a resident stud, and in place of a sensuous nurse trying to kill the patriarch with sex, there's a malicious niece trying to, uh, kill the patriarch (her uncle) with sex.
The problem with this movie is that the actress playing the niece, while certainly cute, is not all that great of actress and is neither a very sexy nor very evil presence. (The movie gets a nice spark out of Orchidea Santis, but she disappears about halfway through). If only they'd cast someone like Ornella Muti, Jenny Tamburi, or Leanora Fani as the niece, this would have been a much stronger movie. The bigger problem, however, is the XXX inserts. The (apparently headless) "stunt doubles" here are without exception much less attractive than the actors they're doubling and the "bonus footage" is awkwardly incorporated into the film. It also doesn't fit well with the saucy, but relatively innocent tone of the original film (which was obviously more of a softcore/nudie comedy). I also suspect, given the amount of insert footage and the short length of the film that this XXX version of the film is severely cut as well.
Very few of the films in the 70's Italian "erotic family" comedy/drama genre, all inspired by Salvatore Samperi's "Malizia", have gotten any kind of decent English-friendly release (including "Malizia" itself), but this one is in especially rough shape. . .