Found weed in son bedroom in September . He said one off . However on Xmas day son popped out to see mate and came back stinking of weed. He claimed friends mum was smoking it . Told ex in pub when I got hold of him and he wasn't bothered. His mum then had boys for one hour and later advised she could add smell it but stbxh denied it and left for gf house. On sons return found him with 2 bags. Stbxh refused to answer phone so went round gf house. He said I call police so I said fine go ahead and said about weed. He came home and half heartly talked with son and we dumped weed in toilet. Next day friend over and more smells lead to searches and more bags found. Again can't get hold of him he is in pub and its gf weekend without kids so fuck off . Have looked on son fb and found this is what he is using to get hold of weed. Have dates and dealers names etc. . have called community police. Stbxh just thinks I am trying to spilt up him and gf . He has practically moved in with her and has only had son one night and see him once every two weeks or so for an hour. . so shocked and disappointed at stbxh reaction .. Help xx