Johnny Carson was a man who laughed a lot. But, if you’ve watched much of The Tonight Show you may have noticed that it’s rare that a guest on the show could make him truly crack up. Considering his long career in show business this isn’t surprising. He of course hosted The Tonight Show Starring Johnny Carson for 30 years, but before that he also performed with some of the all-time greats of entertainment on radio and TV. Carson himself usually had a shrewd and dry sense of humor, so it was a real treat when you’d catch a guest on his show really making him lose his composure.

Steve Martin on The Tonight Show 1978
Via: Johnny Carson/YouTube

In 1978 Steve Martin was filming The Jerk, directed by Carl Reiner. In his appearance on the show Martin said that he couldn’t stay due to the filming and rehearsal schedule of the movie. He made his exit, but then came back to Carson’s desk in an unexpected turn of events.

You can see Carson quickly exhale a puff of his cigarette- something he did as soon as the cameras were off him and on Martin. By the late 1970s Carson regretted smoking on camera and though he smoked on set, he no longer bandied lit cigarettes about during interviews.

Steve Martin on The Tonight Show 1978
Via: Johnny Carson/YouTube

Carson’s face actually turned red from laughing so hard and it looks as though tears were coming out of his eyes as well. Martin’s explanation for why he came back had Carson in stitches.

In the past guests to the show traditionally moved down the row of seats as more guests came out. But, there was a new trend at the time where really big stars would leave after their interviews because they presumably had better places to be. It made the show less lively, but it was seen by some as a status move- something Martin wanted in on.

Steve Martin on The Tonight Show 1978
Via: Johnny Carson/YouTube

See what Martin said to crack up Carson so thoroughly in the video below.