Don Rickles Hilariously Heckles Jimmy Fallon: ‘I Never Liked You’ (Video)

You can’t teach an old dog new tricks, but you sure can teach an old comedian new jokes.

on Tuesday’s “Tonight Show,” Don Rickles proved that even at 89, he can still leave Jimmy Fallon in stitches.

The late-night host introduced Rickles as “a true original legend in comedy, they don’t make them like this anymore.”

His guest’s compliments were a little more scathing, however, as Rickles told Fallon: “You’re fresh, you’re funny, you’re great … I want you to know something, from my heart, I never liked you.”

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The veteran comic at least had some good advice for Fallon, including to pull his hands out of his pockets, not to come out on stage so quickly, and that his badly injured finger was a “great bit.”

He even pretended to get the NBC host confused with Jimmy Kimmel, and joked that he was leaving to go over to ABC.

“You’re here, you might as well get on with it,” Fallon advised.

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Rickles had been a frequent guest on “The Tonight Show Starring Johnny Carson” and “Late Show with David Letterman” since 1965. More recently, he’s become a comic idol of Fallon’s and was one of Letterman’s final guests before his retirement in May.

Genuinely collapsing into laughter during their latest interview, Fallon said he “wanted to write this stuff down — we’re on five nights a week, we’ve lots of time to fill.”

But he finally got embarrassed when the infamous comic told him, “I can’t picture you making love,” and later when Rickles told Fallon his comedy was “real honest without popping a monkey.”

While Rickles was already 80 when Twitter launched in 2006, he was trending on Tuesday, with many users grateful to hear that he was still alive.