"Informer, you no say daddy me snow me Ill go blame,
A licky boom boom down.
Detective mon said daddy me snow me stab someone down the lane,
A licky boom boom down." - Snow, 1993
It's a 2/3 chance that the remaining Ace you didn't show is the ace of spades because...
You have two Aces, I have one. There's a 1/3 chance I have the Ace of spade and 2/3 that one of your cards is the . Once you reveal that one of them aren't, the chance is 2/3 that the remaining one is, not 50-50.