When Susan, George Costanza’s fiancee on “Seinfeld,” was dispatched after licking toxic wedding invitations in Season 7, George reacted with barely disguised glee. Too chicken to break the engagement but obviously uninterested in marriage, he was lining up dates before the body was in the ground.

“I’ve got the funeral tomorrow, but my weekend is pretty wide open,” he tried in one failed pickup attempt. Even for a show about nothing, many deemed this a step too far.

“Fan reaction: Mostly stunned that the show would have George, Susan’s fiance, react with such joy to her death — but it was pretty much perfectly in character for both George and the show,” as Zap2it.com put it.

But now, in a Wednesday interview with Howard Stern, Jason Alexander, who played George, confirmed rumors that “Seinfeld” ditched Susan because the cast didn’t like the actress who played her — or, at least, didn’t like her comic stylings.

“The story goes that she was killed off because you couldn’t stand working with her,” Stern told Alexander.

Alexander laughed. “This poor girl,” he said. Then came the damage control.

“The actress is this wonderful girl, Ms. [Heidi] Swedberg,” Alexander said. “… I love her. She’s a terrific girl. I love her. I couldn’t figure out how to play off of her.”

Stern: “You’re being kind.”

Alexander: “No. Her instincts for doing a scene — where the comedy was — and mine were always misfiring.”

Alexander said he voiced his concerns to his castmates, who said he was imagining things — until they had to play scenes with Swedberg themselves.

“Finally, they do an episode where Elaine and Jerry have a lot of material with her,” Alexander said. After the shoot, according to Alexander, Julia Louis-Dreyfus and Seinfeld himself reported: “It’s f—ing impossible.”

Louis-Dreyfus allegedly sparked the idea to throw Susan to the wolves — or, rather, to the envelopes.

Alexander: “Julia actually said, ‘I know — don’t you just wanna kill her?'”

And that comment gave “Seinfeld” co-creator Larry David the idea to do just that.

“Every time I tell this story I cringe,” Alexander said, “because Heidi is the sweetest.”

Though Susan perished, Swedberg survives, playing and teaching the ukulele and leading her own band, which is available for gigs in New Mexico and Los Angeles.

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