This happened to me when my youngest was a couple of years old. We took him camping for the first time in our tent, nice weather, and with the in-laws. He started crying when we left home, and didn't stop until we got back home and in the door three days later. There wasn't anything wrong with him, but it wasn't where he wanted to be. That was the last time we went camping together until he was much older. The same thing happened when we took the kids to a restaurant when they were little. No more restaurants until they learned to behave like human beings. We have had parents bring children to the movies that cost us $15.00, and it ruins the evening. It is parents place to take care of this. I will probably catch a lot of flack for this, but this is the way I feel. They are your kids, not ours, control them. My parents knew how to control me, and I didn't put up a fuss unless I had a real problem.
Mike