Praying ...

Tonight I was faced with the very real possibility that after almost two years of sobriety  my ex-husband is back drinking. There have been suspicions over the last few weeks but nothing certain. Tonight he showed up looking drunk and then when I asked him a favor he went off on me and left without our son. He told me to keep him and drove off stopping at the end of the drive to throw my sons stuff on the ground. I pray that I am wrong and that maybe he is just experiencing what they call a "dry drunk". But then I think "dry" or real his behavior is unacceptable is hurting our son. He is afraid to go back to the way things were with his dad drinking. I need to be able to protect him. What are my options to keep him safe if his father is drinking? At 14 can he choose not to go to his dads or do I have to fight to change custody?