A girl comes up to her dad one day and says,
"Dad, what's the difference between realistically and potentially?"

The dad replies,
"Well, dear, why don't you go ask your mother if she would have sex with President Obama for a million dollars."

Looking a bit confused, the girl takes off, comes back a minute later and says,
"Yup, mom says she would have sex with Obama for a million dollars."

The dad then says,
"Alright, now go ask you sister if she would have sex with President Obama for a million dollars."

The girl takes off, comes back a minute later and says,
"Yup, she would have sex with Obama for a million dollars."

Then the dad says,
"OK, now go ask your big brother that exact same question."

The girl takes off, comes back a few minutes later and says,
"He thought about it for a while, but he said that he would have sex with Obama for a million dollars..."

The dad then leans down to his daughter and says...
"You see, dear, POTENTIALLY, we have three million dollars. REALISTICALLY, we just have two whores and a fag."