I understand that some people get annoyed when actors in sketch comedy lose it and break character because they can’t stop laughing. Personally, I think that as long as it doesn’t happen in every sketch — see Jimmy Fallon and Horatio Sanz on SNL — I find it amusing, and no one on SNL has ever pulled it of as well as Bill Hader. One of my favorite sketches ever was an unaired rehearsal sketch of “The Californians” where Hader completely loses his sh*t over and over again, which had a cascading effect on the rest of the cast.
However, I stumbled across this old sketch from The Carol Burnett Show this morning, which features Tim Conway playing a dentist and inadvertently giving himself novocaine, and at a certain point, the late Harvey Korman doesn’t even attempt to stifle his laughter. There’s no point, really: Once Tim Conway — one of the best physical comedians, ever — gets going, laughter containment is out of the question. Hell, Korman is trying so hard not to laugh he’s practically crying.
Just let it go, buddy. Skip ahead to the 5:40 mark, and revel in it. I promise you will laugh.