- Okay, so Cecile isn't the brightest candle in the chandelier, but when Valmonte says, "If you scream and your mother comes running, how will you explain why I have the key to your room?", it still shouldn't take the combined brainpower of Einstein and Newton to say, "I'll tell her I don't know, and she'll assume you stole it or picked the lock". After all, who would you believe - the naif who's been locked in a convent her whole life and was properly asleep in her bedroom until awoken by a man, or the man with a reputation as a clever, scheming cad who enjoys spreading malicious gossip and engaging in depravity?
- Well, Cecile was hiding letters from her lover earlier from her mother. She might have been worried that her mother wouldn't believe her because of that.
- Also, Cecile probably knew from past experience that her mother could see through her lies (which were unlikely to be skillfully delivered) pretty easily.
- She's just woken up, she's scared witless, and Valmonte is a master manipulator. She's at a serious disadvantage. Truth in Television, unfortunately. Many rape victims don't fight back because they're in shock, they've been manipulated into submitting, and/or they fear they'll face serious physical injury or murder and be raped anyway. In any case, there's nothing to stop Valmonte using more force or covering her mouth apart from his desire to fuck with Cecile's mind to the maximum extent.
- How old are Valmont and Merteuil supposed to be? The casting of the film seems extremely unlikely considering women were over the hill much younger then, and Merteuil's obviously supposed to still have sex appeal. In the book, Volanges refers to Merteuil as "someone of your youth", but she's clearly older than twenty-two year old Tourvel. Valmont could still be older than Merteuil, of course, but he doesn't seem to be a dirty old man...
- Glenn Close is older than the character in the book, Isabelle de Merteuil is supposed to be a young widow in her early/mid-20s.
Mind you, established aristocrats of the time didn't look like today's 20-somethings, they married young and made their way into the world at a much earlier stage than we typically do (and I don't mean going in clubs/bars at 21).
Glenn Close was 41 at the time she played the part, indeed older than the character but it worked out pretty nicely (she can certainly fill the shoes of a cunning and experienced woman!); but John Malkovich was 35, which is about right for the character of Valmont.
- Besides, over the hill for a first marriage is one thing- for an affair or a second marriage quite another (the folk culture of the time has plenty of references to the sexiness of 'experienced' widows- not old ladies perhaps, but not teenagers either) (Also, while the aristocracy did indeed usually marry young, everyone else actually tended to marry in their mid-twenties anyway. They're just a little less conspicuous historically.)