The Boyfriend's son, Terror, is only 15 months younger than Princess D. Our kids have spent 3 long vacations together and numerous "play dates" on Skype. Even though Princess D has always referred to Terror as her little brother, it is on this trip I believe a real sibling bond is developing.
Terror is naturally competitive and wants so much to prove to Princess D, that even though he might be younger, he can keep up with her. When we get to a flight of stairs he screams "I want to be first!" When a button for a lift or crosswalk needs to be pushed he screams "I want to push it!" If Princess D is holding The Boyfriend's right hand Terror will want to hold it refusing to hold the free left hand. If we are eating a meal he has to eat more than her. Getting dressed becomes a race of who can win, and if he doesn't win then he declares that it wasn't a race after all.
Princess D has taken most of this in stride with the understanding that he is younger and someday he will grow out of this phase. There have been a couple of instances when Princess D has simply had enough of the "little brother" behavior reducing her tears of frustration and us having to adjust their behaviors.We set ground rules like making them take turns pushing buttons, or making him hold the door open for everyone if he insists on being the one to open it.
Then there are the moments when they just play together, or when he helps her with her video game, or when he wants to cuddle with her to watch a movie before bed, or when he insists that she sit next to him, or when he told a waitress that Princess D was his "big sister". Those are the moments when she remembers that Terror is the "little brother" she wants around ... even if he always wants to go first.