Summer time is often family time, and in some families, that means your dog may be joined by other dogs or kids they don't live with. Some advance preparation can help ensure a happy time for all. You will see I tend to err on the side of caution, as I find that if the first few gatherings go well, future gatherings are easier and less management is required as the expectations have been set from the start.
Often emotions run high when we first get together. People are busy greeting each other, often hugging and exclaiming. Kids and dogs arriving may be full of energy after the trip. This can be a prime time for canine chaos. Therefore, consider how your dog might react in advance. If you think they will be extra wound up from the excitement, then consider getting the initial greetings out of the way before involving your dog in the mix. Perhaps a leash would be a good idea to prevent any jumping up or accidentally scaring kids - some dogs get very excited and forget their size, potentially knocking over kids from enthusiasm.