Angelina Jolie has revealed she is scarred after "experimenting" with knives with an ex-boyfriend in bed.Angelina Jolie is scarred after "experimenting" with knives with an ex-boyfriend.The actress - who is currently expecting twins with partner Brad Pitt - says the incident, which caused scarring on her abdomen and thigh, happened when she was 14 and "curious about vampires" She said: "When I was 14, I collected knives. My first boyfriend and I ended up getting into some fighting in bed and being silly. People think that happens every time I go to bed."It was actually something he never wanted to do again. It was a mistake and we really hurt ourselves. It was just being young, you know, when you're curious about vampires and that kind of thing. Just experimenting. It was an accident and I ended up in hospital."Angelina reportedly married first husband, Jonny Lee Miller, wearing a shirt with his name written on it in her own blood. She and her second husband, Billy Bob Thornton, wore vials of each other's blood around their necks.