Matinee Wives (1970)

Yes, totally bored with their husbands in bed, horny Hollywood-Hills housewives Linda Devlin and Pat Chandler have become Matinee Wives. For some time now, they’ve been turning "matinee tricks" with the horny hubbies of other frigid suburban housewives by housewife-turned-madam Kay Gavin, a supersexed entrepreneurial vixen who likes to "curl up with a warm vibrator" each morning to jump-start her day. So, of course, when Paul and Tom make plans for some "outside stud," who do you suppose they call? That’s right: the vibrant Madam Kay herself! And who do you suppose she sets them up with? Right again: each other’s wives! But the kicker is: no one knows this, neither the husbands nor the wives, as they’re all chipping under false names and no one has met the other’s spouse before! So all four are swapping partners and no one’s the wiser.