In 1953, Slioor met both Prince Bertil of Sweden and Erik von Frenckell, a nobleman and married Mayor of Helsinki, at a society event in Finland. While she reportedly befriended with Prince Bertil and kept in touch with him over the years, Slioor and Von Frenckell became lovers, and several newspaper articles were written about them at the time. Slioor and von Frenckell openly attended various events in Finland, and they also travelled together around Europe, including Austria, Switzerland, and France. At Brussels World's Fair, they attended a ball held to honour Princess Margaret of England, and Slioor played piano four hands with her. They also explored the fair in the same group with the Princess.