blow smoke up someone's ass
blow smoke up (one's) ass
rude slang To speak deceptively to one, usually in an attempt to mask true feelings or the reality of a situation. I think they're blowing smoke up my ass about giving regular raises to their employees—I couldn't find any evidence to support that claim. Did my singing sound good? Come on, be honest—don't just blow smoke up my ass.
blow smoke up someone's assAMERICAN, INFORMAL, RUDE
If someone blows smoke up someone's ass, they praise them in a way that is not sincere. Everybody tells you you're great when you're famous, but my mother refused to blow smoke up my ass.