Steve Martin and Martin Short are quite comfortable on any late-night sofa, dating back decades. Steve Martin rocketed into comedy history while strumming his banjo, throwing in a few of the magic tricks he learned in high school, depicting hilarious scenes like giving his cat a bath—using his own tongue. Martin Short cut his comic teeth on SCTV before becoming quite at home on Saturday Night Live, with the unforgettable characterizations of Ed Grimley and Jimmy Glick.

Neither of these giants, in stand-up and sketch comedy, took to the stage when they stopped by “The Tonight Show with Jimmy Fallon” on May 3, but they still had anyone watching in stitches, especially when the host challenged them to play “Best Friend’s Challenge.” Without any props, apart from pad and pen, the partners had everyone falling to the floor in laughter with their responses.

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They also proved, in the end, that they know each other well enough to finish each other's sentences.

Perfect punctuation is a must

Even before Jimmy Fallon [VIDEO] could fully explain the rules of the playful competition, akin to “The Newlywed Game,” Steve Martin got up from his seat to add an apostrophe to the word “friend’s” on the label of the question box, designating possession with correct grammar.

Martin Short shot in with “Someone finished high school!” The fun was just beginning.

The round got underway with, “If Martin won the lottery, what would he buy?” Steve Martin responded rather lovingly that friends would be Short’s acquisition, while Martin Short responded with “a facelift, but this time with a real doctor.”

Losing his pen, Short shrieked “It came alive!” before describing what liquid Steve Martin would be. He quickly offered skim milk, saying, “he looks like a glass of skim milk.” Martin answered the question with a question, writing, “Why would I want to be a liquid?” Seeing the flourish of the paper-tossing was more than worth watching.

Both guests had to put some thought into their recollection of most embarrassing moment for the other. Martin Short recalled an incident when Steve slapped Barry Manilow, thinking he was Martin, while Steve Martin brought up the time when Martin “became confused” in a restroom [VIDEO] and dried his hands on the man next to him.

Martin Short admonished “Go to hell” as he tossed his reply.

The final challenge was to complete the sentence, "Steve has the greatest---,” and both came up with “collection of Nazi memorabilia” as answers.

Fans cannot get enough of this kismet comic partnership as the legends wrap up a current stint of their tour of “A Night to Forget for the Rest of Your Life.” Beyond their impeccable timing and instant improvisation, the comic geniuses’ genuine fondness for one another carries the show.

A bluegrass nightcap

Steve Martin has often graced the stage with his eloquent expression through banjo strings and verse, and the distinguished member of achievement in the International Bluegrass Music Association’s Hall of Fame even recruited Stephen Colbert [VIDEO] to join him in harmony last fall. On this night, however, Steve Martin chose to stay seated on the sofa, next to Martin Short, and introduce the band he has played with for more than ten years, the Steep Canyon Rangers.

Recognizing the band’s 2018 album, “Out in the Open,” Martin was like a proud papa, and the musicians did not disappoint as they tore into the affirming title song.

Lead singer Graham Sharp was a delight with his double-fisted harmonica virtuosity. Nicky Sanders’ fiddle doesn't just dazzle, but definitely reminds listeners that bluegrass is one of the few forms of music still dedicated to the beauty of real instruments and real musicians creating magic on stage.

The tune topped off a perfect night of friendship and fun with a flourish of lively harmony.