to two-time
01
裏切る, 不貞を働く
to betray one's partner by secretly having an affair with someone else at the same time
例
She was devastated when she found out he had been two-timing her with her best friend.
彼女は、彼が彼女の親友と浮気していたことを知ったとき、打ちのめされた。
