Little Johnny joke: The difference between "potentially" & "realistically"?'

Young Johnny goes up to his father and asks him, 'Dad, what is the difference between "potentially" & "realistically"?'

He thought for a moment, then answered, 'Go ask your mother if she would sleep with Brad Pitt for a million dollars.

Then ask your sister if she would sleep with Brad Pitt for a million dollars, and then ask your brother if he'd sleep with Brad Pitt for a million dollars. Come back and tell me what you learn from that.'

So the boy went to his mother and asked, 'Would you sleep with Brad Pitt for a million dollars?'

The mother replied, 'Of course I would! We could really use that money to fix up the house and send you kids to a great University!'

The boy then went to his sister and asked, 'Would you sleep with Brad Pitt for a million dollars?'

The girl replied, 'Oh wow! I LOVE Brad Pitt I would sleep with him in a heartbeat, are you nuts?'

The boy then went to his brother and asked, 'Would you sleep with Brad Pitt for a million dollars?'

'Of course,' the brother replied. 'Do you know what a million bucks would buy?'

The boy pondered the answers for a few days and then went back to his dad.

His father asked him, 'Did you find out the difference between 'potentially' and 'realistically'?'

The boy replied, 'Yes, 'Potentially', you and I are sitting on three million dollars ...

But 'realistically', we're living with two hookers and a queer...