My three year old niece is in her choice phase. Every time I’ve seen her in the last six months, I ask for a hug and she smiles and says “noooooo!” Then rushes to give my wife a hug. I just let it go because she’s said no and that means no. Then usually later in the day she’ll pop around and give me a huge hug then. I’m hoping that means she learns that no means no, so when a boy later on tries to make it a “yes” she’ll make him understand it really does mean no.