After the fact
This is a phrase that you say when someone does or says something but they have no idea that their timing was totally and stupidly wrong. Oftentimes, people will say it with the word "all".
Example:
How you gonna go to the movies with everybody, leave me behind, and then tell me that the film is good and I should go see it ALL AFTER THE FACT??
How you gonna go to the movies with everybody, leave me behind, and then tell me that the film is good and I should go see it ALL AFTER THE FACT??