Complex sentence: In 1938 his mother and father bought a half double house with son Leonhard and his wife, causing Elser to feel cheated and severed all ties with his family excepting his sister Maria in Stuttgart.
Split into simpler sentences: In 1938 his mother and father bought half a of double house in collaboration with their son Leonhard and his wife. Feeling left out in the cold, Elser severed all ties with his family excepting his sister Maria living in Stuttgart.