I don't want to get approval from my wife to spend $5000.
That sounds like a bad idea. Are you sure you want to spend that kind of money without your wife knowing?
Listen, no one at my home likes to have fun, I just want to have some fun.
You should ask permission first. Hiding makes it worse and she is bound to find out sooner or later.
It's not like my family knows what fun is, I'm going to spend the money then I'll accept the blame when she finds out.
It is good that you are going to accept the blame, but your marriage is in big trouble if you start hiding your finances from your wife. The secrets will cause fights and your marriage will probably end.