In the book, “Welcome to Dunder Mifflin: The Ultimate Oral History of The Office” (via Uproxx), Krasinski recalls how he rejected the ill-conceived kiss with Cathy, saying:
“That’s the only time I remember ever putting my foot down. I remember saying things that I never thought I’d say before, like, I’m not going to shoot.
“My feeling is that there is a threshold that you can push our audience with. They are very dedicated. We have shown them great respect. But there is a time when if you push them too far, they will never come back. And I think if you show them Jim cheating, they’ll never come back. “
Creator Greg Daniels wanted to worry audiences that “he was going to give them a bad ending so they would be happy when they had a good ending.” However, Krasinki’s reasoning convinced him and eventually, although he made his way to Jim’s hotel room in Florida and tried to seduce him, the show never treated Cathy as a real threat to Pam. Instead, he had Dwight (Rainn Wilson) come to the rescue, when Jim called him and convinced him that there were bed bugs in his room.
Cathy, some kind of overgrown bed bug, would walk away with Dwight’s chemical spray on her face, and Jim and Pam would stay together without any shark-jumping kisses between him and other women. All’s well That ends well.