These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Cry for the Devil: Annette knows that Kathryn is ultimately responsible for Sebastian's death through what she read in Sebastian's journal. Many photocopies of it are then made and Anette gets Cecile to distribute it to the other students at school. Kathryn is delivering a eulogy for Sebastian in the chapel when someone enters the church and quietly lets the higher-ups know what is going on. Everyone begins to exit the chapel, prompting an outraged rant from the normally composed Kathryn. She storms out, demanding an explanation....and soon comes to realize that everyone now knows the whole truth about her. As she stands in shock, the school's headmaster comes up behind her and detaches the crucifix from her necklace....causing a trail of cocaine to spill out. This prompts tears of shame from Kathryn to end the movie on a Downer Ending.
Sequelitis: Both sequels, with the third one being In Name Only sequel. Cruel Intentions 2 though has a dubious distinction of originally being a failed pilot (killed by religious groups, when they found out that the pilot, called "Manchester Prep", featured a scene where a Cecile expy learns about how to orgasm while riding a horse) / stealth reboot set shortly after Sebastian and Kathyrn's parents married and the two becoming allies and featured stand-in characters for Cecile and Annette. When the pilot was ultimately rejected, the film was given a new downer ending (the Annette stand-in turns out to be an evil bitch friend of Kathyrn, designed to break Sebastian and drive him to the dark side) and gratuitous nudity scenes inserted into the film as it was released direct to DVD.