Well...

My wife is a lawyer, and I'm pretty well versed in law regarding food service, having been a slave to that system for three decades.

Does this make me eminently qualified to comment? Probably not. Is that gonna stop me?

Oh, hell no!

I live in, I believe, the most litigious society in the history of the human race. I say this not to brag, cuz it's nothing to be proud of, but just as an illustrative point.

And I believe that has, under American law at least, provided the answer to your dilemma.

Now, Boris and his boys aside, I am fully aware you live in a much more civilized society than mine. I mean seriously, y'all meet the bare minimum of having universal health insurance, at least...

But litigation clarifies things. Or at least makes certain things explicit. In the United States, if a company allows refills on a thing, or gives it away with a dine-in meal, they usually explicitly state, somewhere highly visible, that refills must be consumed on the premise. They wouldn't do this if it had not been litigated at some point. Capitalists are basically lazy, so if they hadn't had to pay a settlement or defend this idea in court at some point, it wouldn't be posted in a highly visible manner. Your twisted logic has, at some point in the past 40 years, been litigated, and your position lost.

Now clearly, the U.K. is not the U.S. But y'all do tend to have a penchant for copying our most egregiously banal lawsuits...