A little black number and a lot more besides
Coco Chanel said that "you can be gorgeous at 30, charming at 40, and irresistible for the rest of your life." She was applying this to women. I wouldn't restrict it.
Coco lived a remarkable, and sometimes controversial life into her eighties. She became one of the richest women who ever lived, having started out life in poverty. She made the money herself. She never married, but had numerous affairs. Another memorable observation was to "jump out the window if you are the object of passion. Flee it if you feel it. Passion goes. Boredom remains."
We have Coco to thank for making sunbathing and suntans fashionable. And for her many pithy observations including the view that "as long as you know men are like children you know everything." Again, she never married. I also like her comment that "in order to be irreplaceable, you must always be different."