Tucker likes to come up to my office, sit at the other desk and play brother and sister. "Can we play brother and sister, Mom?" This game consists of him sitting at his desk fussing with stuff and prattling away while I sit at mine fussing with stuff and giving occasional answer, and we're not allowed to use our usual names, we have to refer to one another as Brother and Sister. "Is that good, Sister?" "Yes, Brother." One time he climbed up in the seat and said to me, "Can we play Mother and kid? You be the mother and I'll be the kid. Ok, Mom?" Stopped me dead in my tracks. "Ok Tucker. Ok Son. Let's play that."