This man is the father of Sandra Green and the maternal grandfather of Amy, Rachel and Jill Green. This relationship makes him the great-grandfather of Rachel's daughter, Emma Geller-Green. He is an unseen character on the show; he is mentioned in The One With The Lesbian Wedding when Sandra says that she never worked and she went straight from her father's house the sorority house to her husband's house and then Sandra tells Rachel she's just so proud of her.