we call SILS boyfriend jesses 'uncle' and i always write OH as uncle in my nieces birthday cards etc,
with my aunties an uncles if iv grown up with their partner i call them aunty or uncle, not so much any more just certain ones, but for instance my uncle is getting married in a few weeks i wouldnt refer to his wife as my auntie even though iv call her jesses great aunty if you get what i mean LOL,
i call my mums friends 'aunty' still too haha xx