In reality, paternity court proceedings are dry as dust. DNA samples are taken. They are sent to labs. A conclusion is almost always clear and is rarely made in person. Judgment enters. How they can make a reality TV show about it defies me.
In a related note, over the last several centuries in modern Western Europe, the long term, per generation cuckoldry rate has been estimated to be on the order of 0.91% to 2.0% per generation, using genetic tests and very long genealogy records available in the European region of Flanders.