It seems to me that any sentence that starts with “You’d better not” is a threat, and, if a reason is given, then that reason is something bad that will happen if you do what you’d better not do. So, the whole song Santa Clause is Coming to Town is a threat, and Santa coming is the bad thing that will happen if you don’t watch out.
It seems to me that any sentence that starts with “You’d better not” is a threat, and, if a reason is given, then that reason is something bad that will happen if you do what you’d better not do. So, the whole song Santa Clause is Coming to Town is a threat, and Santa coming is the bad thing that will happen if you don’t watch out.