How often should you throw out underwear? Expert reveals something totally unexpected about the shelf life of women’s knickers

How often do women really need to toss out their underwear?  We’ve had many debates with pals in the past over how many days in a row we can get away with wearing the same bra.  Yet we’re all in covenant that we need to put on a original pair of pants day after day.  But when it comes to women’s knickers, there is one thing we’re not…