Is it okay if I threaten someone, but not really mean it?
Why would you make a fake threat?
You can do it as long as you don't mean it. People don't really like it, though.
I've never heard that you can threaten someone as long as you don't mean it. It's never right to threaten someone, and you could get in trouble with the law.
I can go to jail for something I didn't mean? That doesn't make sense.
Yes, even if you deep down didn't mean it, the other person doesn't know that and the threat is very real and valid on their end. Additionally, it's simply a mean thing to do. Please do not threaten people as a form of entertainment, for their sake and yours.