Quite early on in my search I found out that my paternal great grandfather was a bankrupt bigamist - he abandoned his wife and youngest child, left his 18 year old pregnant daughter out in the lurch (my great grandmother), ran away to Nottingham, added a "de" into his name and had a child with a woman who we (a half cousin and I) believe that he never married.
I'm glad though, otherwise I wouldn't have that said cousin, and who knows, I may not have been here!