It was frighteningly close to what he believed of his father at the worst moments - that he really was the kind of man who would send a letter signed "Sincerely, Cpl. Peter Vilmos" to someone he'd seen naked.
The protagonist experiences a troubling realization about his father, leading him to a deep discomfort. He reflects on the idea that his father's character, when at its lowest, could resemble that of a person capable of sending a deeply personal letter to someone he had seen in an intimate state. This brings forth a sense of dread and confusion about the nature of his father's love and morality.
This moment serves as a critical turning point in the narrative, highlighting the complex relationship between the protagonist and his father. It raises questions about vulnerability, respect, and familial ties, ultimately reflecting on how personal connections can be marred by feelings of shame and fear.