We have a 13+ year old Maximillian Pionus that has lived almost his entire life in our home. He is not much of a biter- will occasionally gently nip me or one of my sons (adult) after we've had a crowd here (like after Thanksgiving). He is not a party bird. My son's girlfriend is around more and more and he is HORRIBLE. He flies right at her and bites- hard. I've had her give him a treat, he takes it hesitantly, eats it and then attacks. Nothing describes it better. He dodges me and goes in for a bite very aggressively, even flies at her like a missile beak open to bite. She is a gentle girl and none of us can understand it. We have plenty of other people coming and going and have never seen this behavior. In the midst of the attack I can get him on my arm easily, but he then flies right at her and is biting. It is almost impossible to keep her safe in the moment. He is like lightening. Needless to say if she's here he is cage bound. Does anyone have any insight?