As Rihanna is exiting the building, someone (her bodyguard?) steps in front of her and opens the door for themselves, not realizing that every action has an equal and opposite reaction.
Ergo-- door flies open, door flies closed...and unfortunately, Rihanna was right in its path.
After the door smacks into her, Rihanna is understandably angry and yells "Thank you!" to the person behind her, whom she was maybe hoping could have seen the slam coming and somehow stopped it.
Check out the video above and tell us what you would have done.