"You know me so well, luv," Callahan answered, because you couldn't possibly have chips without salt and vinegar. "Maybe I should marry you. Genius here says that having coffee is as good as a proposal, but getting the food right merits a ring for sure."
He grinned at Mac. "Do you want anything else, or can we leave the young woman alone now? Girl's got to work for her tips." He'd seen his mum make a lot more with the tips than her salary, so he didn't want to keep her too long.