Gary Lipowski:

Gary Lipowski (David Anderson) Nicknamed "Fingers". Gary Lipowski is Leon and Brett's dad. His wife is not shown, suggesting/implying that he is a widower. He owns a repair shop for things
Leon's dad
like radios and televisions and microwaves. In the episode "School Trivia Night" he was thought briefly to have stolen the Flunes' television and donated it to the school.