Now xians believe that jebus was the son of their sky daddy. But anyone who knows anything about biology would realise that you need a mother. So if your sky daddy was jebuss father who was his/her mother?
Now xians might say that amoebas dont have mothers however that would mean that yor sky daddy is a single cell organism and so this is a messed up analogy.
Or maybe Mary was however how can an invisible firend have sex with someone?