I have a problem with jeans. I can never find a pair of jeans that fit me properly. I often put this down to being in between sizes and so having to go a size up in order to get the jeans to fit on the waist. But I then find that the jeans seem to be falling down all the time, and hence I spend the day hitching them up again, even when wearing a belt. As a consequence, I think jeans are possibly my least favourite item of clothing. So when F&F launched a new collection of limited edition shapewear jeans, called the ‘Bum and Tum’ collection, I…