The casting couch is a term used to describe a situation where someone who has the power to give you a job, like a director or producer, asks you to do inappropriate things, like take off your clothes or have sex with them, in exchange for a role in a movie or TV show. It is very wrong and illegal because nobody should be forced to do something they don't want to do for their career to grow. If someone ever asks you to do something like that, you should tell someone you trust and report them to the police.