He specifically situated himself at the door to greet guests, welcome friends, and introduce himself to any newcomers through at least the first thirty-five minutes or so. If your character arrived during that time frame, he definitely said hello to you. If Zee was nearby, he would initiate introductions. After the initial arrivals, he'll spend most of the evening circulating the main floor areas, including the patio, and chatting with friends, making certain people have a drink, and have found the food, and generally being a host type.