Sparkling Cyanide 1983

About 6 minutes into the film in a scene lasting over 2 minutes, Christine Belford walks into a hotel room presumably from the en-suite. She is wearing a shiny mini-fullslip with generous lace at hem and bust, and shoestring straps. I'm not sure how best to describe the colour, possibly purple, I'm tempted to say plum. Her boyfriend of 6 months is waiting for her. They are both married to someone else. Inexplicably given what she's wearing he decides it's time to end their affair.