IMDB:
https://www.imdb.com/title/tt0254653/
Looking at a summary from Suspect Video this sure is a movie we should get our hands on:
From its opening barrage of disorienting images – suburbia, S&M, affluence, a nude orgy, with the film’s titles and credits perversely withheld until the very end – “Pamela, Pamela you are…” is obviously an attempt at something other than a mere nudie. In fact, it comes off as a Sixties-style mix between the groovy mainstream of films like Richard Lester’s Petulia and the sordid underbelly of director WILLIAM L. ROSE’s earlier Rent-a-Girl.
[...] Before the day is out, Pamela and Susan both end up colliding at Calvin’s apartment (when Susan discovers his collection of chains and S&M toys, Calvin coolly explains, “I’m just a collector!”) which makes things between mother and stepdaughter a tad strained. “You horrible, filthy son of a bitch,” Pamela screams before Calvin tears her dress and spanks her.
All of which occupies roughly the film’s first 40 minutes. Things really go insane from here on as we spend the next 30 minutes or so at a kinky sex party Calvin throws at Pamela’s place featuring guests getting their clothes torn off, and a guy dressed as a Nazi, and a gal wearing a giant papier-mâché head, and a gal getting mauled in a coffin, and a guy getting into a catfight with a butch lesbian, and a chain fight between two guys, and a variation on spin-the-bottle with a naked gal getting spun around, and other sexploitation-film debauchery.
[...] She imagines all the party guests dressed as priests and nuns and filing out of the house to surround her and watch impassively as Calvin beats the bejesus out of her with a stick.
That would make Elaine Edwards (40) and Mary Lindsay the spankees and Paul Hardy the spanker.