A new greeting

The yellow bus/blue bus exchange between Can and I has developed into something of a greeting. The other day I came home from work and Can was sitting on the potty. He couldn't see me come in the door, but when he heard the door open he yelled out from his place on the porcelain throne, "DADDY YELLOW BUS." I of course responded in kind with a hearty, "NO, DADDY BLUE BUS." Then yesterday morning after he woke up, his mommy was carrying him from his bed. Through bleary eyes, he spied me said, somewhat less enthusiastically, "daddy yellow bus." I kissed him on the head and said, "good morning," to which he responded "daddy pokey face."