In a scene where Jerry and Sidra are hanging out in his apartment, Elaine — who had previously "accidentally" felt Sidra up in a sauna — suddenly shows up. Sidra immediately realizes Jerry had sent Elaine to the sauna to check the authenticity of her breasts and decides to break up with him. Before leaving for good, she said the iconic line, "And by the way, they're real, and they're spectacular!"
Teri Hatcher still remembered how that scene went. Regarding "Seinfeld" co-creator Larry David, she told Rolling Stone, "Larry may remember this differently, but in terms of the now-famous line... when you were taping in front of a live audience, Larry would feed you lines. He'd say, 'Okay, go through the door, turn this way, and say this.'" She further explained, "I remember that being one of the lines he fed me when, after I'd said it, it just stuck. I don't think it was the original script; I'm pretty sure he just came up with it on the spot. Larry David deserves all the credit for the joke working so wonderfully. Well, Larry and Mother Nature, I guess." (via Vanity Fair).