"The One With Christmas In Tulsa" is the tenth episode of season nine of Friends. It aired on December 12, 2002 and is fifth clip show of the series.
Chandler must spend Christmas in Tulsa to finish work that needs to be completed before Christmas Day, and he knows he will be fired if he refuses to do it. He will therefore not be able to spend Christmas in New York with Monica and others, which makes all six of them, particularly Chandler and Monica, unhappy. This is what leads the episode into a clip show showing clips from previous Christmas related Friends episodes, as Chandler and the rest of the gang remember previous years where he spent Christmas with them.
Chandler feels empathy for the employees underneath him, who are depressed because they can't spend Christmas with their families, and sends them all home. However, the regional vice president of the Oklahloma branch of the company, Wendy, who is mentioned to also be a former Miss Oklahoma runner-up stays behind to help him, at which point, Monica and the others call him to wish him a Merry Christmas. When he makes the mistake of mentioning Wendy, and that she has stayed behind to help him after he sent all his other employees home, Monica gets suspicous and grills him, leading to him accidentally making it obvious to them that he is attracted to Wendy, but he promises Monica that there is nothing for her to worry about. When he hangs up the phone however, Wendy then hits on him. He politely rejects her, saying he's a happily married man and nothing can happen between them because what he has with his wife is great, but then she responds by asking him why he's spending Christmas with her instead of with his wife if what he has with his wife is so great.
Meanwhile, back at the apartment, the other five friends gaze out of the window as they see that it is snowing, but Monica is too busy worrying that Chandler is having sex with Wendy to think about anything else. But then Chandler proves her wrong by walking through the door at that very moment, much to everyone's delight. And he assures them that he can't be fired after all for spending Christmas with them...because he has resigned.