My much-younger cousin stole some sports memorabilia from my house. I knew it had to be him, he was over at my house, I showed him the stuff, later on he was the only person alone in the room where it was, after everyone left it was missing. I called his parents and just said, "Hey, [your son] stole my stuff, I know kids take things sometimes but I'd like it back and I'd like to talk to him about why it hurt me that he would take something of mine and why I hope he'll never do anything like that again."

They responded, "How dare you! Our little angel would never steal anything!" I was so shocked by their response that I didn't even know what to say and hung up.

Heard nothing for two days, called them back and said, "Look, my stuff is gone, if you're seriously claiming your son didn't take it I guess I have to call the police, report it stolen and answer all their questions about who was the last person to see it." At that point they admitted that they already knew their son stole the stuff when I called them the first time but that they were embarrassed so they denied it. Then they asked if their son could keep some of it because he really loves it! And when I went to their house to retrieve it they acted like I was being a jerk taking a kid's toy away from him. Our relationship has never been the same since then.