WIFEMISTRESS -- K-B Cerberus and K-B Janus.

The quaintest, and possibly also the most extreme, of feminist pictures is, of all things, "Wifemistress" with Marcello Mastrianni.

Set in an Italian village early in the century, it tells of a wine merchant whose childish wife is malingering in a futile attempt to attract his attention. She doesn't know that this elegant, aging playboy who wears furcollared coats is also an active anarchist.

When he must disappear, leaving clues that he has been murdered by a thief, she gets out of her bogus sickbed and sets out on the bill-collecting rounds he normally performs.

But he actually is hiding in a loft next door to his own house, and observes his wife as she fills the vacancy he left. On her rounds, she discovers more and more about him -- that he was a well-known pamphleteer on atheism and women's emancipation, that he kept various mistresses and lodgings, that he indulged in kindly friendships and kinky sexual arrangements -- and she gradually takes over all of these activities for herself. She gets so deeply into his life that she captures the attentions of his mistresses.

One sees mostly Mastroianni's apined eyes, framed through attic slats as he peeps down on the unfolding story, weaker in the role of the ignored spouse than even she was. He tries to denounce her new life as corrupt, and to assert that she has not the intellect or the culture to leave the church for freedom of thought. But finally he must bow in pain to the realization that she has outdone him in every area he chose for himself.

It is Laura Antonelli's film, as she moves from the blank life of the wife into the sexually and ideologically complicated life she inherited. From her pouting-child bed scenes to her explicit erotic ones, there is an orchestral development.

Marco Vicario has provided a storybook atmosphere -- the clop-clopping of the slow horse in which these wine-merchant rounds are made punctuates the film -- that gives a cleverly crafted story the charm of a parable. The only trouble is that, like many cleverly moral folk tales, it goes on far too long after one has gotten the idea.