Complex sentence: When he was a youngster, Del always was told to call Freddie "Uncle Fred" then, years later, when Granddad got drunk one night at an old folks party he told Del all about the affair.
Split into simpler sentences: When he was a youngster, Del always was told to call Freddie "Uncle Fred". Then, years later, when Granddad got drunk one night at an old folks party he told Del all about the affair.