Adultery, British-style--in a thin, shakily drawn-out sex comedy that's rarely amusing and occasionally just distasteful. The reluctant adulteress here is Ginny Barnes--the sexually timid, Catholic-reared, suburban wife of often-impotent businessman Ian. And the man who changes her life is an old school chum whom Ian re-encounters one day in Harrods: posh playboy-psychiatrist Caldos de Roche, who is invited for dinner and immediately turns all his beefy, bearded, charismatic, suave attentions on Ginny. So the seduction process begins--including Caldos' giving Ginny's beloved father-in-law a caretaker job in London--and it isn't long before Ginny is finding pain/pleasure ecstasy on the floor of Caldos' flat while the Missa Solemnis plays in the background (""she hardly knew whether it was Beethoven she was worshipping, or God, or his detumescent penis leaking sperm""). Religion-connected guilt ensues, of course, as does a VD scare (a nightmarish clinic examination). But ""she loved him with a wild, rude, boastful, furious love""--and when Ginny comes to believe (mistakenly, Ã la bad situation-comedy) that Ian is equally unfaithful, she continues with Caldos and takes excursions into public sex (at the opera, in church), sado-masochism (belts, hairbrushes), and other variations. But finally Caldos' psychiatric irresponsibility leads to a suicide--which turns Ginny off. So it's back to Ian, though now with the benefits of Caldos' sexual tutelage. Implausible and glossily seamy overall, then, but bored housewives who like their adultery fantasies graphic and kinky may find some vicarious titillation here.