He's pleased at her ready acceptance of his condition, and not just because it means he'll be sure she gets home safe this one night. He really is bone-tired, and in no mood to argue. He's actually hoping the night air, that's bound to be brisk this time of year, revives him enough that he'll not have to fight to stay awake until he gets home himself.
Standing up as she leaves, he cleans the table and puts the bottle away. He'd paid for their drinks earlier, so all that's left to do is meet her as she returns, a tired smile on his face. "Let's get our coats and blow this popsicle stand, shall we?"