Blow smoke up (one's) ass American informal rude slang
To tell someone something or compliment someone in a way that you do not really mean so.
Though he sounds as if he is praising me, I can see he is just blowing smoke up my ass.
Only when she failed miserably in the beauty contest did she realize that her false friends had been blowing up her ass about her beauty all the time.
You blew up my ass. Therefore from now on, I won't believe you anymore.
The verb "blow" must be conjugated according to its tense.
The origin of this slang is not clear.
To talk the main part at once, or avoid talking about what is not important
You should get straight to the point.