Let's see. You're what? 13? and you switched jackets with a 20-year old friend? and you're calling him worthless? I guess that's normal for a lot of 13-year olds to switch articles of clothing, but not for adults. When you become a grown-up, I'm sure you would understand why your girlfriend got upset.

In addition, if she bought your jacket for you--as a birthday gift or Christmas gift, or for whatever reason, and you gave it away to someone else, that would be reason enough for her to be to be mad--because she bought it for YOU--not for him. AND, if you did it right in front of her, that's reason enough for her to be furious!