fait accompli
noun /ˌfeɪt əˈkɒmpliː/
  /ˌfeɪt əˈkɑːmpliː/
[usually singular] (plural faits accomplis 
 (from French) /ˌfeɪz əˈkɒmpliː/
  /ˌfeɪz əˈkɑːmpliː/
)- something that has already happened or been done and that you cannot change- We got married secretly and then presented our parents with a fait accompli.
 Word Originmid 19th cent.: from French, literally ‘accomplished fact’.