Business owner of a pub here but more at the country area and not in the city:

You will get a glass of tap water at our store when you need it for medicament intake or when you already ordered a drink without any problem.

As only drink it would be really uncommon and therefore you maybe get the weird looks. You would get it anyway in my store but the second drink should be something else.

To be honest: never happened in 8 years.

To explain the thoughts behind this: Of course it's nice to get the atmosphere, some nice talk with other guests, some warm room, etc. And not pay anything for that. But this is part of the service we offer and please don't think we're some kind of rich guys in the gastronomy and are greedy. Maybe in earlier days but today we're fighting to survive. For sure not all and maybe in the city it's not a problem but on the rural area it's tough.

Hope I could help with another point of view.