Umm, well first of all, hi there, and did he do anything else to you? Whose stress toy was it? I'm guessing it might be child abuse, I'm not sure. Well, one thing's obvious, NEVER BREAK ANOTHER STRESS TOY EVER AGAIN. Maybe tell someone you trust a lot? IDK, I'm not a great helper in these types of situations, sorry! But I do hope this helps! <3
I hope you're okay! If anything like that happens again, you should really tell an adult.
~ Your friend, Wraya <3