Unavailable - I dont mind the term 'breast' when associated with breastfeeding or when I am at the GP's.
But when using it with my DC it just seems to be impersonal and formal.
My DC know exactly what the correct term for boobies are but we are a fun household and thats the way it is.
My Mother was always so straight faced about such things and not very open with us and when she spoke of breasts it was always said in a way in which implied she really shouldnt be speaking about such things, so I guess maybe thats why I prefer Boobies or boobs.
Its funny now though we are all grown up my mum has started saying it, but can tell it still makes her feel uncomfortable.