"Don't be a sap," Aidan replies without missing a beat, "you could have grown on me." A dazzling smile at that. "I've always paid for my drinks, no exceptions. You'll learn."
This certainly wouldn't be one. If he still had a throat by 'next time', of course, or drinking might prove a bit problematic. But the point was, the point, that too many coppers used their status to drink on the house in speakeasies, and he wasn't one of them. If he was going to go and do something illegal, he was going to spend his own dough doing it.