When jokes, remarks, postcards, or films are saucy, they talk about sex in a light, teasing way that is meant to make you laugh, not to shock or to be truly dirty. British English uses this a lot: a saucy joke, a saucy wink, the old saucy seaside postcard. It feels playful and a little old-fashioned. Though actually the same word has other lives. In British speech a saucy child is one who answers back — cheeky, not sexual. And of food, saucy can simply mean covered in sauce. The teasing-about-sex sense grew out of the older ‘bold / cheeky’ sense; sauce itself once meant rude talk as well as the stuff on your plate. The sexual sense is still the light one: if something is cruel or openly pornographic, saucy is too small and too kindly a word.