It’s normal to want to know why it can or has happened. It’s nothing to do with who you are, or what you’ve said or done. Some people want to feel power and control.
They know what they’re doing is wrong. They might tell you to keep it a secret or try and make you believe that it’s okay. This is called ‘grooming’ which is a way to build up trust with you so they can keep abusing you. Grooming also happens online.