So do you guys think it's a good idea to tell his parents about it ? To search of they find some twelve words it's a key to some hisen coins ? Or what do you guys think?
First of all, condolence to you bud and rest in peace to him.
You should tell his parents that he/she has bitcoins stored in his wallet 'cause it might help their family. I don't find any problem with it telling them since Bitcoin isn't a bad thing. If they ask about it, you'll be the one who should be responsible to answer all of those questions since you're the one who will tell about it. I hope you find the keys to his wallet, good luck mate.