Blowing bubbles

Making plans or agreeing to something without the intention of actually following through.

Lying or “blowing smoke”

“ hey I thought you said you were on your way” “oh, man I’m not gonna make it” “pssssss… You were blowing bubbles up my ass the whole time weren’t you?

OR
“Hurry up man, I’m waiting for you outside. Don’t be blowing bubbles”