Here's a conversation I had with Jack a few nights ago.
Jack: Can you marry your brother?
Me: No. It's not allowed. You can't marry any of your close family, brothers, sisters, children, mums or dads. Not sure about Aunts and Uncles, but probably not. You can marry your cousin but it might not be a good idea. Anyway, your cousins are boys.
Jack: Can men marry men and ladies marry ladies?
Me: Well, sort of. It's called a civil partnership.
Jack: And can men and men have babies?
Me: They can..... but they still need a lady to do it.
Jack: Because only ladies make babies?
Me: Yes, only ladies can grow babies inside them
Jack: So can ladies and ladies have babies?
Me: Yes, but they still need a man to be part of it (please don't ask how that works!)
Me: Because you need a man and a lady to MAKE a baby. Every one has a mum and a dad even if they don't live with one of them.
Jack: Can you get unmarried?
Me: Yes, it's called a divorce.
Jack: Will you and Daddy divorce?
Me: I certainly hope not!
Jack: Can you marry more than one person at a time?
Me: In some places in the world you can, in some places a man can have more than one wife. It's called polygamy. But you can't do that here. Here if you marry more than one person at once it's called bigamy and it's against the law.
Jack: Can you go to jail for it?
Me: Yes, I think so.
I'm pretty sure that at 5 years old I hadn't given much though to straight relationships, much less same sex marriage, and the complications around starting a family in one. And trying to explain about polygamy and bigamy? Really? I think I am in way out my depth here..... Can we go back to talking about "Is there a God?"