How do we deal with ungrateful party guests? My husband and I are more financially stable than my?

... sisters. So when we have parties, we try to plan activities and have food my sisters and her kids will enjoy. Something they usually will not do on their own. However, we are now at the verge of not wanting to have any more parties because we feel that they are now having certain expectations of us and have a sense of entitlement that we must fulfill for them.

For example. We just had a birthday party and due to the heat, we purchased a water slide for all the kids to play in. This is the first time we ever purchased such a thing. We set the party to start at 2. My sisters called and asked if they can come earlier at 12 to play in the water slide. I had to tell them no because we are not ready.

Now once the party has started and the kids were playing for 3 hours, we wanted to transition away from the water slide to other planned activities. We stated numerous times the water slide will be shut down in 10 min and every1 must change into their dry clothing. All the guests changed, except my sisters kids. The parents stood silent and did not say anything while we kept repeating ourselves. I had to literally call each kid by name to get out of the pool.

Close to the end of the party, my mom in law informed me that she packed up extra food a long time ago for my sisters to take home. I kindly informed my sister about the extra food. Instead of a polite "thank you," she said "I know. Your mom in law pqcked up food for me a long time ago. Had I asked you to pack up food for me, you would have said wait till the end." Arghhh!!! Im the hostess. My job is to ensure everyone had enough to eat before I pack up leftovers. But she did not understand that. Thats what frustrating to me.

This is not the first time my sisters behave this way. It just feels as if its getting worse and my husband and I feel as if we are.responsible for her kids having things they cannot provide themselves. Needless to say, we did not enjoy our own birthday party and now are thinking of cancelling all future parties. Am I overreacting? I want to tell my sister how her actions are making us feel, but we do not want to shed light on their financial struggles. Any advice?