I will preface this by saying this is simply research, the details are not completely fixed but it takes place in England.
John and James are partners in a small law firm.
A woman comes to their firm seeking a divorce. She first sees John and shortly afterward begins a relationship with her. He also begin paying for some things like her bills as she was a SAHM and she doesn’t have enough money after her split to pay for everything.
James soon takes over the case (he’s the family law specialist); he knows about the affair. He represents her in her divorce then she moved away to be closer to family.
The affair stops.
A decade or so later, all is revealed. How much trouble are they in?
By the way, John is married with kids (born before and after the affair), not a free agent in any way.
Just wondering what you would expect to happen here.