The Phaedra complex is kind of like when you feel really strong feelings for someone that you shouldn't be feeling, like a family member or maybe someone much older than you. It's named after a character from an old Greek story named Phaedra, who had a crush on her stepson.
So, let's say you have a really cool cousin who's a lot older than you. Maybe they have a car or they're really good at video games, and you think they're just the greatest person ever. But you start to realize that you love them in a way that's not just normal cousin love. You might feel embarrassed or confused about those feelings, but it's very important to remember that it's not your fault and it's not something you should act on.
It's kind of like a secret feeling that you have to keep to yourself and you have to learn to deal with in a healthy way. You might talk to someone you trust, like a parent or teacher, about those feelings and they can help you understand it better. It's all about learning to manage those emotions and not acting on them in a harmful way.