We're planning a surprise birthday party for my father. It's going to be a casual event. We know that he would not want gifts, just the presence of his family and friends. I've been put in charge of invitations and need to come up with some way of saying this besides "No presents, just your presence," as my mother doesn't like that. I'm not the one who decided no gifts, I'm simply in charge of figuring this out. Any suggestions?