Long story so will try to keep it as short as possible. My dp's birthday is new years eve, so I planned a party for him, it was a BBQ and people were told to bring their own drinks. My DC went to their father's house for a week and it because of that we had said no children. People all got back to me and said they were coming and that was all good. No one mentioned about bringing children or extra people. We supplied all the food which we did based on the numbers who said were coming. On NYE one couple turned up with 4 extra adults and 2 toddlers. My DP and I were not exactly happy about this but did not say anything as it was DP's father's house and we did not want to cause any trouble at his house. There are extensions going on at the house so we said if the toddlers were going to go outside they needed to be supervised, there is also an old dog who is friendly but I did not think a toddler should be left unsupervised, especially since the dog has arthritis and I did not want the dog to snap at the toddler. DP's father and I were outside at the BBQ, organising the meat. The BBQ is at the side of the house so we cannot see the garden from it. Nobody told us that the toddlers were outside. We suddenly hear a scream so we both run around to the garden and one of the toddlers is sitting near the extension work and crying. He had scraped his arm on a nail. I take him inside to his mother who then complains that she needs a break as well and it's NYE and it was not fair that I wasn't watching her son and did not deal with the injury. DP's father told her there was not supposed to be any children here in the first place, that we had no idea that she was coming and she was told to not let the toddlers out the back unsupervised.
My DP also had enough when we realised they were drinking our drinks because they did not bring any and said that it was enough and the toddlers had to go home (it was about 9pm at this stage). These people are now bad mouthing us on Facebook and I have received messages off their friends telling me how unreasonable we were. So WIBU?