My ex and I have open custody. Ds x 2, (aged 13 and 4) live with me during week and see ex for one day at weekend, stay over every other weekend. We divorced because of his unreasonable behaviour. Drink and drug issues amongst other problems! He wants to take both boys camping at weekend with other male dad and son. Have serious concerns about his ability to cope and look after youngest son, whilst remaining sober. How do I stop him without him kicking off? What would you do?