You were forced to get the dark mark by Voldemort and you try to protect Blaise’s reputation…

Dumbledore: “paramedics saw the mark y/n. I understand that you are scared to talk about how you got hurt, but it wasn’t your fault…”

You: “I’m trying to be respectful but this doesn’t concern you.”

Dumbledore: “you are a student 17 years old… it does concern me. Was it someone you know? Was it Blaise Zabini?”