Mrs. Robinson (The Graduate)

Mrs. Robinson is the primary antagonist of both the novel and film adaptions of The Graduate and is arguably one of cinema's most notorious and well-known seductresses, who is infamous for her affair with a much young man and her manipulative, even abusive, means to try and keep him from marrying her daughter.

History
Mrs. Robinson is introduced as the wife of Benjamin Braddock's father's law partner and successfully seduces the twenty-one year man in secret despite being in her fortys - the two continue to have an affair for the summer but Benjamin realizes he and Mrs. Robinson don't share much in common beyond sex, Mrs. Robinson eventually opens up to Benjamin and claims to have been in a loveless marriage and accidentally got pregnant with Elaine.

Benjamin's parents and Mr. Robinson all want him to call Elaine and begin courting but Mrs. Robinson forbids it in secret - despite this he and Elaine go on a date but Benjamin deliberately sabotages the date, only to have a change of heart as he realizes Elaine was someone he was comfortable with and he had been treating her unfair.

Mrs. Robinson, however, becomes furious and begins to threaten Benjamin with exposing her version of the affair, which in turn prompts Benjamin to admit the affair to Elaine, yet it is revealed that Mrs. Robinson had lied to Elaine and claimed that Benjamin had raped her while she was drunk, this makes Elaine refuse to believe that her mother had been the one to seduce Benjamin.

After many talks Benjamin and Elaine start to overcome the web of lies and confusion only for matters to worsen when Mr. Robinson learns of the affair and becomes angry, threatening to have Benjamin arrested if he comes near Elaine again - forcing her to drop out of college to marry Carl, a classmate who she had a brief relationship with.

Desperate to prevent this Benjamin breaks into the Robinson home in hopes of finding Elaine, only to be confronted by Mrs. Robinson, who informs him he won't be able to stop the wedding and proceeds to call the police, claiming her home was being burgled.

Overcoming all the odds against him Benjamin does manage to stop Elaine's marriage, a brawl ensues as guests try to stop the pair from leaving together, with Elaine breaking free of Mrs. Robinson and slaps her - the pair then flee on a bus and head to an uncertain future.

It is unknown what happened to Mrs. Robinson after this, at least in the film (the novel had a much less successful sequel known as Home School)

Trivia

 * the quote "Mrs. Robinson, you're trying to seduce me, aren't you?" has gone down as one of cinema's most iconic quotes - the scene in which it is uttered has also gone down as one of the most famous examples of a femme fatale style interaction on film.