Pumpkin Eater

Catherine and Jane were married.
Cathy and Anne were engaged.
It all went terribly wrong when Cathy caught Catherine and Anne sleeping together and told Jane.
Ending in a fight and a break up for both relationships.
But what Jane and Cathy don't know is that maybe one of them isn't at fault, and was only trying to protect the other, being forced into the relationship under threat.
Will they be able to save the unwilling partner?