DS comes from a separated and blended family.

Here DS only has myself. He has cousins that he is close to but for all intents and purposes in our home he is a one and only.

At his fathers house he has a 'step' and 'half' brother, so two other siblings.

DS is 4 and a half. DS and I have essentially never lived as a family unit of more than us two.

Until recently we have avoided the whole 'I want a sibling' scenario. Its just never come up. Until now. DS has asked if we can take one of his cousins (baby - 18 months now) home and keep her. He has told me that he wants me to have a baby and asked me why I cant just put one in my belly. He is adamant and no amount of talking has been able to sway his mind. In the end Ive ended up just telling him that it is what it is and its not going to change, which of course he is not happy with.

How do you handle this? What do you say? His little heart is breaking (taking mine with it as it is still a sore point with myself anyway) and I just want to help him to understand but to also feel comfortable about the fact that it is just him and I and thats okay too.

Anyone who is walking this path would love to hear from you. Thanks