We are planning a trip to visit my parents abroad. My parents plan to invite a lot of relatives to visit while we are there. Many of them will be coming to see us on Shabbos. Is that okay? It is their house and their party. They will, however, be inviting people in our “honor”. Do we have to say anything?
I think you should let them know that you are very uncomfortable with the idea that your relatives are driving on Shabbos to see you. Can you arrange for a Sunday picnic or barbeque? Should explaining your feelings fail to make a difference, there is not much you can or have to do. Be careful not to encourage anyone to come who will have to drive to do so.