Complex sentence: He is often annoyed and disappointed by Adam's seeming laziness and reluctance to take any real responsibility, not realising his son's dual identity, but none-the-less is still very proud of his honest and kind-hearted son.
Split into simpler sentences: He is often annoyed and disappointed by Adam's seeming laziness and reluctance to take any real responsibility. Not realizing his son's dual identity, he is still very proud of his honest and kind-hearted son.