Betrayed and abandoned by her boyfriend on wedding day, Kalina has decided to open unusual business that will once and for all solve problems of male fidelity. She decided to help women testing loyalty of their partners. Everything goes well until Kalina has to seduce Maciej – coach and specialist in female - male affairs. His wife Beata suspects that he is cheating on her and wants to have irrefutable evidence. Kalina, knowing class “opponent” starts working with redoubled energy, but this time all her plan goes wrong. Maciej is not like other man whom were easily caught cheating.