Conan O'Brien Is Hilariously Incensed That BTS' J-Hope Called Him 'Curtain': Watch

After all, you can't spell TBS without BTS.

Conan O'Brien has been a staple of late night TV for nearly three decades. The longest tenured host in the wee hours -- who began his run in 1993 when he took over the Late Show on NBC from David Letterman -- recently announced that he's wrapping up his TBS show on June 24 before moving to HBO Max. He's clearly an icon, but that doesn't mean the towering carrot top is a global superstar.

"I gotta say, when you go through a change like this, it gets a guy thinking about stuff ... and without sounding too high falutin', I have started to wonder a little bit about, 'Gee, 28 years on TV, day in and day out every night, what's my impact been? What have I meant to the world?'" O'Brien mused on Wednesday night's (May 5) show.

Well, just take it from actual global superstars BTS: not much.

The K-pop boy band were recently on a South Korean variety show where they played a game in which they were asked to identify various celebrities. O'Brien knows this because on Wednesday night, he played a clip from the program in which J-Hope was shown a pic of Conan and confidently blurted out "Curtain."

He immediately collapsed in convulsive laughter as his bandmates Jin and Jimin playfully scolded him for not recognizing the talk-show host. "Conan! How can you not know Mr. Conan!" Jin said. J-Hope giggled in response, "I got confused for a moment!"

Conan, however, did not find it quite as funny. With a stern, straight face, he deadpanned, "Curtain. He called me Curtain!"

Longtime sidekick Andy Richter tried to put some salve on the unintentional burn, offering, "Well, it's like the whole world is convening to wish you well on your new endeavor and, you know, we're drawing the curtain ..."

"He said I was a curtain! I've been to Korea!" O'Brien bellowed hilariously. "I was popular! 'Curtain!' I'll get you BTS, oh I'll get you good. And by that I mean I'll silently resent you." On Friday (May 7), J-Hope offered his apology, tweeting pouty face and writing, "Sorry,,,,, Curtain," along with kissy face and blowing kiss emoji.

Well, if it really stings that bad, maybe he can soothe it with some "Butter," the band's upcoming second English-language single arriving May 21.

Watch the curtain rise and apology below.