Thank you for your advice. Two remaining doubts - how on earth can I prove that my ex partner made that statement in the first instance? I could of course have made the whole thing up. That said, I do recall specifics, namely that the mother deliberately cut a hole in her contraceptive diaphragm. Would that add weight to it's genuineness? Secondly, whilst the book is all about them, they will have vaguely ficticious names, so could that be classed as anonymising them? It would remain pretty evident who I'd be referring to nonetheless.