So I have found out that my recently turned 13 year old has used Mandy the day after his birthday with his mates older brother and his friends, I know as one of them got him on Instagram with a video of him doing a key, I've took all the money he has got from his birthday (ten pound was lost from it, not sure if he used it.), but I have no idea how to go about it now, anyone able to help? It might seem I'm calm and collected but really I'm ready to throw him out a top story window for doing this shit.