This man is the husband of Susan's Mother. He is the father of Susan and the father-in-law of Wyatt. He is the maternal grandfather of Penny, Randall and Lisa. He is the ex-maternal grandfather-in-law of Zack Johnson and the current maternal grandfather-in-law of Leonard Hofstadter and Lisa's Husband. He is a great-grandfather to Penny's Nephew. Penny, Lisa And Randall's Cousin may be his possible grandson.
He is indirectly mentioned after Professor Proton asks Penny if she has any single grandmothers and she ans were that both grandmother's were married.