Well, if Cake didn't want it then Nightwing wasn't going to make him eat it. He just shrugged and started in on the other half.
"I know," he told X wryly. "Thanks for proving me right that I could trust you two alone for two minutes." Not that it would be happening again if he could help it. And not that he wasn't fully expecting to get reamed out by Batman for it later since he was sure the man was watching and he glanced up almost unconsciously in the direction of one of the hidden cameras.