When the under-wire in your bra pops out and pokes you in the tender underside of your bosoms - throw it away as soon as you get home.
Otherwise, you will put it in the wash, then wear it again unwittingly. When the errant wire pops back out and pokes you again, you will swear and curse, as you will be in the car, driving to work. You will then spend the day wishing you had thrown the damn thing away the first time, cause now you have to look all "professional" while the wire of doom pokes you repeatedly.
I'm just sayin' is all.