Angelina Jolie insists her five-year-old son MADDOX was a crucial factor in her decision to become involved in a committed relationship with Brad Pitt. The couple are parents to Maddox, as well as ZAHARA, 23 months and SHILOH, six months. She explains, "We left a lot of it up to Mad, and he took his time and then made the decision. One day Maddox just out of the blue called him Dad. It was amazing. "We were playing with cars on the floor of a hotel room, and we both heard it and didn't say anything and just looked at each other. So that was probably the most defining moment, when he decided that we would all be a family." Jolie insists she had already initiated the process to adopt daughter Zahara when her relationship with Pitt became serious saying, "We both saw her picture in a file on the same day, and we both went to Ethiopia to see her, and we both had the same fear because she was sick at the time, and we both made the decision that no matter what, we were going to look after her." Jolie gave birth to the couple's biological daughter Shiloh in May (06) and says the moment they brought her to back to their house she made their family complete. She adds, "The day Shiloh came home... we looked around at three sleeping children and each other and thought 'My God! Here we are! This is amazing!' We can't even figure out how to get them all in the car!"