I've name changed for this as this is embarrassing 
My neighbour has a 6yearold son, he's friends with my DD and comes in our garden to play with them, whenever he's here I've called him Darian as that's what I thought his nan called him when we first met. Today, it's my DDs birthday and he gives her a card, his name is actually Damien.
DD has also been calling him Darian 
I have no idea why we've never been corrected by him. His father also calls him Jacob, the poor boy must be so confused if he was being called 3 names!