Daddy, I fell in love

Son : Daddy, I fell in love & want to date this awesome girl.

Father : That’s great son. Who is she?

Son : It’s Sandra, the neighbors daughter.

Father : Ohhh I wish u hadn’t said that. I have to tell u something son, but u must promise not to tell your mother. Sandra is actually your sister.
The boy is naturally bummed out; but a couple of months later :

Son : Daddy, I fell in love again n she is even hotter!

Father : That’s great son. Who is she?

Son : It’s Angela, the other neighbour’s daughter.

Father : Ohhhh I wish you hadn’t said that.
Angela is also your sister.
This went on couple of times and son was so mad, he went straight to his mother crying.

Son : Mum I am so mad at dad! I fell in love with six girls but I can’t date any of them because dad is their father!
The mother hugs him affectionately and says :
My love, you can date whoever u want.
He isn’t your Father..!!