Kramer was dating Leslie, a clothing designer. Jerry and Elaine were invited to dinner by Kramer, but Jerry complained that Leslie was a "low talker", meaning that no matter how hard he tried to listen to her, she was never loud enough to be heard. At the dinner, when Kramer excused himself for the restroom, Jerry accidentally agreed to wear Leslie's latest design on his upcoming appearance on The Today Show: a pirate-inspired puffy shirt. He tried to back out, but Leslie had already sold some retailers the shirts under the condition that Jerry would wear it on TV.
At the taping of The Today Show Jerry broke down in front of Bryant Gumbel while wearing the shirt and told him that he hated the shirt and was only doing it because he made an accidental promise. Leslie then screamed, extremely loudly, "You bastard!"
Back in his dressing room, Kramer was consoling Leslie, but when a happy George entered and started making fun of the shirt, Leslie snapped and pushed him into an iron, burning his perfect hands. ("The Puffy Shirt")
Leslie makes a brief appearance in “The Finale”, and takes the stand to testify against the "New York Four". However, nobody (including Arthur Vandelay, who is sitting right next to her) can hear her, and Jackie Chiles makes her leave the stand. ("The Finale")