Sam's latest obsession

Each time I have a new baby the next oldest child has displayed some type of interesting behavior. I have never had problems with them trying to harm the baby or act out towards the baby, they have always loved the new baby. I have simply noticed a strange change in behavior not necessarily directed toward the baby. Jacob needed to be held everytime he drank his milk after Carter was born, Carter started pooping his pants after being potty trained for three month once Sam was born. Sam's new obsession has been the most intersting of all, but what else would I expect from Sam. He has his own baby, his baby Lola. He calls her his baby, carries her around everywhere with him, and cuddles and kisses her. When Brett is holding Natalie he says, "oh Daddy you are holding your baby and I am holding my baby." When I was giving Natalie a bath the other day he went and got Lola and gave her a bath too. He told me, "Mommy you gave your baby a bath and I gave my baby a bath." Poor Lola, she is so patient with him when he sqeezes her a little too tight or lies on top of her while snuggling her a little too much. I just hope she makes it through the summer.