Me and my husband separated just before xmas last year and rightly or wrongly I intermittetly check his facebook messages. I have just seen a number of messages to a number of different people asking if they could get drugs for him. This happened on a night when he had our 2 daughters over night. I cant take it to the police or solicitors to stop him being able to have the children over night as there is technically no proof that the drugs were for him and if I tell him I have seen the messages then he will change his password and I wont know if anything like this happens again in the future. What should I do?