You searched for: “inconstancy
inconstancy (s) (noun), inconstancies (pl)
1. The condition of changeability; unpredictability: Nancy promised Doug to go to the movies with him, but she suddenly decided not to, and so he never asked her again because of her inconstancy.
2. The problem of falseness; faithlessness; infidelity: Tom's inconstancy over the months shortly after their marriage caused his wife to dissolve it as soon as possible.