The story begins with a normal evening of a normal looking family in US. Married couple with a girl and a boy. The girl was older if I remember correctly.
Suddenly there was an alien invasion at night/evening, the housewife revealed to be an alien agent (there is a "take off human mask" scene I remember) and the daughter was also its species. They eliminated the coming police and army.
But while landing, alien ships were destroyed by some more advanced Earth forces (kinda XCOM feel) and the mother and the daughter were beaten by the husband and the son.
Turned out the husband was an agent of Earth and human already knew the agent and the invasion.
At the end, the husband told the aliens to accept the defeat and went back to the daily masquerade. Then he threw the mask back to the wife and said something like he used to her old face.