This was recently demonstrated by Maggie Wheeler, who played Janice in the show. In a recent interview with Cosmopolitan she pointed out a moment in a scene that most of us have probably never noticed .
Watch it and see if you spot it...
In The One With The Giant Poking Device, from the show's third season, Chandler finds out his girlfriend Janice has been seeing her ex-husband behind his back.
"Chandler discovers that I've been fooling around with my ex-husband and I'm breathing into a paper bag," Wheeler said.
"I'm hyperventilating and we had rehearsed it many times, and every time he would just grab the bag gently and the air would just exit it."
But as the show was filmed live in front of a studio audience, it didn't quite happen as it was scripted to.
"The adrenaline was pumping and we were in the middle of the scene," Wheeler added.
"And he was like 'do you love him?' - yes - 'do you love me?' - yes - and he just grabbed the bag with more force than he had in any rehearsal and it popped. By the grace of God I was able to hide my face in the bag, but you can see if you look at it, he almost cracks up."
If you look closely there's definitely a smirk on his face as he tried to avoid cracking up, although he does decent job holding it together.
Source : The LAD Bible