One scene has Glenn Close in bed shot from profile, and the sheet in down exposing her breasts. The film cuts to a frontal shot and the sheet is up around her neck. When it cuts back to profile, the sheet is down again.
The opera that Glenn Close buys the tickets for is Madame Butterfly. That is the song she is listening to when we see the first signs that she is losing it. Note: At the end of Madame Butterfly the heroine kills herself over a lover. In the director's cut of Fatal Attraction Glenn Close cuts her throat in the bathroom of Michael Douglas' house thereby killing herself over a lover.