Jack Geller is the father of Monica and Ross Geller. He is affectionate to both his children; lovingly calling Monica his little har-monica. However, some of his actions do help to feed the assumption that Ross is the favored Geller child. Jack unknowing used boxes of Monica's childhood memorabilia to prevent flood damage to his Porche, ruining everything. Also, he reveals to Monica after she becomes engaged to Chandler that the Monica wedding fund was spent on a beach house, as he and her mother thought she would never get married.He has four grandchildren named Ben Geller, Emma Geller-Green, Jack Bing, and Erica Bing. Later in the show, he forgot that Ben was his grandson, probably because he doesn't see him much since Ben is raised by Ross' ex-wife and lesbian life partner, and he wasn't there for his birth. Monica named her son after him. Making Jack Bing his second grandson.