Quantum Love (2014)

Pierre has been happily married for fifteen years and a good father. Still in love with his wife, he enjoys his wife and family and is content. One evening, he meets Elsa at a party and are immediately attracted to each other. Fifteen days later, they happen to meet again and the mutual attraction turns into infatuation. But his love for his wife and Elsa's rule about not dating married men prevents them from taking the next step. Instead, they fantasize about each other, and soon the fantasies mingle with the reality.