flake on (one)

slang To cancel or renege on a prearranged meeting, event, obligation, etc., especially at the last minute. This is the second time in a row that he's flaked on me the morning of our date. I'm giving him one more chance, but after that I'm done with him. I need a business partner who isn't going to flake on me before an important meeting, Janet. I'm sorry to flake on you like this again, but I'm just too tired to go out tonight.