Complex sentence: At the start of the work he is ashamed to acknowledge his non-aristocratic lover Fenichka, but with the example of ideals in practice presented by the nihilists, and finally with the approval of his brother, he marries her.
Split into simpler sentences: At the start of the work he was ashamed to acknowledge his non-aristocratic lover, Fenechka. However, with the example of ideals in practice presented by the nihilist, and finally with the approval of his brother he marries her.