I thought that was “Suddenly Last Summer.” She was good-looking in “Butterfield 8” as well. Regarding screen actors and actresses from the 50’s and 60’s, both the men and women were much classier then. I don’t know why, too much fluoride in the water, perhaps.
“Suddenly, Last Summer” is the one with the white bathing suit. Montgomery Clift is in it too. It has a colorful and sordid plot. Liz is a mental patient and Katharine Hepburn is her aunt. Her male cousin was using both of them as sexual bait for Spanish street urchins, but the latter turned the tables on him and cannibalized him (yes!), the sight of which drove Liz crazy. Clift is the psychiatrist who saves her from a lobotomy because Hepburn wants to eliminate her memories.