Close-Up Perfect with Dummy Pen

Show a dollar Bill (which may be borrowed) and a ball point pen.
Tap the bill with the pen, then pushes it right through the bill!
Display both sides of the Bill clearly, - the pen actually penetrates the bill.
He now rapidly slides the pen over and off the surface of the Bill apparently tearing it.
There is no hole in the bill, which is completely unharmed.

You are supplied two ballpoint pens. One is ordinary and the other is cleverly gimmicked.