'If the situation with my sister is like this, then why am I not telling her anything?'
Reaching this point, Christian found himself wondering about his own behavior. After all, holding back from discussing Eva and avoiding the topic had only led to awkwardness and discomfort between him and his sister earlier.
Christian immediately found the answer: it was primarily because she was the mother of a girl who was his age. However, it wasn't simply about the complexities of her being a mother or the age difference; he didn't mind discussing either aspect with his sister after all.
It was actually about her material state, as he still had not broached this subject with Eva. He had even tried not to think too much about it, as it was an uncomfortable question, with an answer that he feared could be dreadful for him.
He didn't have the courage to ask this question, and seeing how she continued with the older sister setting, he followed along with her.