Talking 'bout babies

As mentioned A. is expecting a baby brother or sister next month, and we explained to the boys that his mommy has a baby "in her tummy" (I added, "In her womb," but I don't think anyone heard me). When she arrived to pick him up that afternoon they greeted her with, "You 'ave baby in dere? Baby in tummy?" and when she agreed that yes, she did indeed have a baby "in her tummy" they interrupted with pleas to "Open! See baby!"