I agree that you should keep him on a leash until he calms down. He's just a pup himself. Perhaps you should take him for a really long walk, or spend a few hours throwing tennis balls for him to chase so that he's really tired when the girls arrive. Do you have siblings? If the girls are due to arrive at a certain time, say 7 o'clock, could you bribe a family-member to take him for a walk while they all arrive? That would at least relieve some of the "oh-my-goodness-company-coming!" excitement! And remember - a tired pup is a good pup!