On one side my great grandfather married one sister, had children with her, then when she died, married her sister - found that sister was not the same as original wife (she was a teetolar, he owned a pub), felt forced to change, sold the pub, couldn't cope so comitted suicide - leaving three children with a step-mother who was also their aunt in control of the money, who definitely did not want children. My grandmother was left bringing up her younger brother, whilst having to work and earn enough to keep them both.
So my great great aunt is also my step great grandmother. She decided she wanted to be buried with them, so bought the plot next to her sister (where husband had also been buried). As she lived for another 50 years or so, that was fun finding the paperwork to prove ownership of the plot. (She used to visit it regularly to make sure it was still vacant.)
On the other side my grandfather's sister had one child out of wedlock, left him with her parents, and ran off with another man and married him. She used to visit once a year but wasn't allowed out of the kitchen. Then she became married to another man, and had more children. There appears not to have been a divorce between these two marriages, and according to the marriage certificates I have found, she got younger rather than older. The grandchildren from this second marriage were not happy (understatement) when they connected to us via family history searches and found more about their grandmother than they had bargained for!
Another one - no proof of anything, but I wonder how one set of my great grandparents were able to afford for the wedding they had complete with photographs, when one worked in the kitchen of the "big house" and the other worked in the gardens.
Have others, some fact, some "spoken history" but most don't mean anything to anyone outside the families.