"You convinced me, actually. At the END End. I wanted to bugger off BEFORE the Boss came. You were the one being all heroic," Crowley said this guiltily, as again, he shouldn't have stayed with him at that point, but it seemed that where Aziraphale was concerned 'shouldn't' was the word of choice.

Crowley....
...shouldn't care about Aziraphale.
...shouldn't be wondering WTF 'special' meant.
...shouldn't be nearly purring at the comfort of being on his angel, and petted by him.
...shouldn't have approached him in Eden.
...shouldn't have agreed to the Arrangement.
...shouldn't have stood with him at the End.
...shouldn't have plotted with him before hand to try and taint the Antichrist.
...shouldn't have run into a burning building thus risking his corporation after him.
...shouldn't have grabbed him and ran for help the second he knew the angel was in danger.
...shouldn't feel this way about the angel.

Ngk. WHAT way? But then again, Crowley knew all too well that he really really really couldn't face the answer to that question.