Motsi Mabuse knows that when people meet her for the first time, they are expecting to meet a showgirl. The former pro dancer and Strictly Come Dancing judge has flown in from her home in Germany this morning but, post-photoshoot, she is wearing a baggy black sweatshirt, leggings and trainers. It’s funny, I say, but I don’t think I’ve ever seen you dressed down. “You will never see me dressed up ever, unless I’m on TV,” she says. “My sister in South Africa, she’ll call me on FaceTime and be like, where’s the girl from TV? Who are you? I’m…