After giving his daughter a present for her 18th birthday the father went on to give her a cheque and said
-Father: My daughter I have been giving your mother cheques every month for the past 17years for you maintanace but now you have turned 18 I am no longer bound to do so, so please tell you mother I said 'its over, you shall never again get a dime from me' and with an evil grin he added 'take a pic of her face when you tell her, I want to see the expression!
The next weekend the daughter came back and the father asked..
-Father: did you take the pic? show me..
the daughter showed him the pic and in it the mother had an sinister smile..
-Father: Why is she smiling?
-Daughter: She told me to tell you I am not your daughter..
Then the daughter took a pic of the father

^^^^^^^^