My DS, who is two and a half, is a very friendly little guy to his sister... Like, too friendly. He hugs her from behind and won't let go. We've taught her to say "No hugs!" and taught him that he is supposed to let go when she says this. It doesn't seem to have gotten through his head, though. Yes constantly grabbing on to her, almost tackling her, wanting hugs from her. He doesn't really do this to anyone else. I'm not quite sure what to do here. Any other suggestions as to how to make sure he respects her space when she tells him to?