double-dealing
🇺🇸
/ˌdʌbl ˈdiːlɪŋ/
🇬🇧
/ˌdʌbl ˈdiːlɪŋ/
Being dishonest by pretending to be loyal to more than one person or group, but actually helping only oneself.
His double-dealing was exposed when his two allies discovered they were both being betrayed.