Jason Alexander, who played George Costanza on Seinfeld, did not get along with Heidi Swedburg, who played his love interest Susan on the show. Ali Wentworth, another Seinfeld co-star, confirmed that the two actors didn't seem happy around each other during filming. Alexander discussed having trouble working with Swedburg on the Howard Stern Show and even joked about killing her character off. Alexander later apologized to Swedburg on Twitter for his remarks, describing her as a kind and lovely person who worked hard to create Susan. Despite this, Susan's character was eventually killed off the show.