" potentially and reality "

Youngest Son: Tell me Daddy, what is the difference between "potentially and reality"?
Dad : I will show you

Dad turns to his wife and asks her: Would you sleep with Robert Redford for 1 million dollars?
Wife: Yes of course! I would never waste such an opportunity!

Then Dad asks his daughter, if she would sleep with Brad Pitt for 1 million dollars?
Daughter: Waow! Yes! This is my fantasy!

So Dad turns to his elder son and asks him: Would you sleep with Tom Cruise for 1 million dollars?
Elder Son: Yeah! Why not? Imagine what I could do with 1 million dollars!
I would never hesitate!

So the father turns back to his younger son saying: You see son, "potentially" we are sitting on 3 million dollars, but in "reality" we are living with 2 prostitutes and 1 gay!"