blow smoke up someone's ass
US /bloʊ smoʊk ʌp ˈsʌm.wʌnz æs/
UK /bloʊ smoʊk ʌp ˈsʌm.wʌnz æs/
1.
to flatter someone excessively, often insincerely, in order to gain favor or manipulate them
:
•
He's always blowing smoke up his boss's ass to get a promotion.
•
Don't blow smoke up my ass; just tell me the truth.