"Pretty certain" means nothing. Until you get something in the mail ignore the person. If you get something the mail, answer it and you might want to take it to an attorney.
No one said don't play games - they said stop playing with children online. Maybe find a hobby that doesn't include children or disgruntled individuals.
There's nothing to "deal" with until you get some paperwork in the mail. Ok actually here's how you deal with it - block the 24 year old. Don't talk to him ever again. Stop communicating with the 16 year old. Move along with life.

