

You would be the bad guy if you make him return it. Personally I would have a talk with your son about how unusual the act is and how his act could be used as leverage over him, nothing is free. Teach him healthy skepticism. Also call back those parents and tell them to fuck off, completly unacceptable they bought something connected and important for your son without checking with you first. They dont know your house or rules…
Edit: the phone isn’t on friends family plan, right?
I was being dramatic, sorry, yes, this!