Besides Karen's parents, there was another thing standing in their way. Denis got recruited into the army, while Karen started college at The University of Minnesota. They were about to separate for a while and, naturally, they feared that the distance would harm their relationship.
However, Dennis remained committed through the most difficult times. He even sent his girlfriend letters every once in a while. Sadly, Karen's father kept all the letters hidden so Karen never actually got a chance to write back. She even though Dennis moved on and their relationship slowly died out.