unfaithful
US /ʌnˈfeɪθ.fəl/
UK /ʌnˈfeɪθ.fəl/
1.
불충실하다
having a sexual relationship or experience with a person who is not your husband, wife, or usual sexual partner:
:
•
If a man was unfaithful to me I'd leave him no matter what the circumstances.