When I was a teenager a girl I liked and hung out with and fooled around with a bit asked me for a ride to a friends apartment to pick up something. I take her and wait outside the security gate in my car. After 30 minutes of her not coming back I finally reach her and find out she left in someone else's car and said she would be right back. I left immediately.

Also when I was a teenager a guy I worked with who I considered to be a friend helped me look for my wallet I lost at work one day. A week or so later some other friends confide in me that he admitted to them that he had actually stolen my wallet after it fell out of my back pocket and took the money and threw the wallet away. I confronted him and made him pay me back the money.