re: WWtOTdo or was I in the wrong?

Personally, I wouldn't do it because it can be seen as an insult. You buy food at one place and want to use space at another place, that sells food as well, so that you can eat your food.

You have to realize that if you are outside.. They don't want people to see people sitting outside of their place, with food from another location. What will people think "well, the food there must not really be that good. Look at those people, they have food from somewhere else". You probably should have went ask them first.

But the waiter didn't have to be a dick about it either. He could have just approached you like an adult and informed you that they do not allow guest to sit at their location to eat food from somewhere else.