Aziraphale was torn. He didn't want to stay - the last thing he wanted was for Belial to give too much thought to the two of them. However, he also didn't want to leave Crowley there and drunk with Belial.>

Finally he gave Belial a polite smile. "Actually, no thank you, dear, I really ought to be going. I just wanted to make sure Mr. Crowley wasn't up to any mischief when I wasn't looking. You're hardly someone he can wile, after all."

Perhaps Crowley could use this to his advantage and flee, although Aziraphale wasn't sure how, or even if Crowley wanted to.