faithless
adj. 不忠实的;无信的;无宗教信仰的
例句
She decided to divorce her increasingly faithless and unreliable husband.
她决定要跟她那越来越不忠实也靠不住的丈夫离婚。
《柯林斯英汉双解大词典》
So receive me brother with your faithless kiss.
那么兄弟请用你不诚的吻来接纳我。
If you don't keep promise, you are a faithless person.
如果你没有守承诺,你是不可信的人。