inconstant
adjective literary uk/ɪnˈkɒn.stənt/ us/ɪnˈkɑːn.stənt/
(尤指在感情、行为或择偶方面)多变的,不忠实的,不专一的
not staying the same, especially in emotion, behaviour, or choice of sexual partner
an inconstant lover 用情不专者
Opposites: changeless constant incessantinvariant never-endingperpetual