In the "The Parking Space", George and Elaine are talking about parking. Elaine tells George to park the car in a garage, he says no. Then, Elaine asks him why. George promptly says "I don't know, I just can't. Nobody in my family can pay for parking, it's a sickness. My father never paid for parking; my mother, my brother,
nobody. We can't do it.
George's brother is also mentioned in "The Suicide", when George says to a psychic "Pauline? . . . Wait a minute. I got it. My brother once impregnated a woman named Pauline."