A Family That Lies

A man bought a lie detector machine that slaps people whenever they lie, and decides to test it during lunch with his family.

FATHER: Son, where did you go today?
SON: I went to school.

( The lie detector machine suddenly slaps the son)

SON: I went to watch a movie at my friend's house.
FATHER: What kind of movie did you watch?
SON: A James bond movie.

(The lie detector machine slaps him again)

SON: (Almost crying now) I watched a blue film.
FATHER: What! when I was your age, I never watched such films!

(The lie detector machine slaps the father)

MOTHER: (Laughing hysterically now) Your son inherited your gene.

(The lie detector machine slaps the mother)