Warning: Pet Peeve ahead.
I'm not sure how much I buy the "You have me at a disadvantage" thing. It's not like Clark couldn't turn Bruce's head into a fine red mist before he could even get his hands on the Kryptonite, let alone bring it into play.
Kinda takes away from the "trump card" aspect when the guy you're using it against knows you've got it and there's about sixteen billion ways he can keep you from using it.