Both should be changed regularly, and both for the same reason.
One Brazillion.
Well it depends on what you mean by change.
So they can speak more fluently
One acts solely for money, the other is the actor.
Hnng. Aaaaaaaah. Like that. I'll show myself the door.
They both need to be changed after a while for the same reason
Someone who shows up to your door for no reason.