A friend you know, who is secretly a ninja. He will deny that he is a ninja, what ever you say
You: Hey Hjalte. Are you a ninja?
Friend: no... no im not
Hjalte is your friend who is a master ninja. He may say that's he is not, but deep down you know it's true
You: hey are you a ninja?!
Hjalte: ehhhhhhhhhh, No! no im not.