Tainted Love?

 From Der Spiegel:

"At first sight they look like an ordinary couple, strolling through the park with their child and their dog. But when the two adults hug each other their physical similarities are unmistakable. They have the same pronounced nose, the same blue-green eyes, and the same thin lips. Patrick S. and Susan K. are brother and sister. They are an incestuous couple."

Dietmar Hipp asks "[m]ust consensual sex between close relatives be punished?"

The high court replies "yes."

This story raises an interesting question for liberty-minded people: if no one is hurt by such a situation (as seems to be the case with the couple in question), should the government have the right to decide the fate of two apparently happy people, regardless of how repugnant such a scenario may strike most folks?