My ex is back in children's lives after 2 years of working/living abroad. My teenage son loves being at his house and is spending more time there than at home. I haven't wanted to stop this as he's old enough to make up his own mind but I recently discovered he is keeping him off school for any little ailment when he stays there and he has been letting him drink alcohol to the extent that I found out a few weeks ago when he was there that he had to be put to bed he was in such a state. He also came home with a black eye and graze on his face which he lied to me about and told me it was from playing about but was fro the same night. My younger two on the other hand don't want to see him as they say he shouts at them a lot (was witnessed by someone who knows us). I've just had a blazing row with my oldest about his father and I don't know what to do from here. Any advice please would be great and apologies for the long post.