Conan O'Brien's unexpected yet impressive cameo on TG4's Irish language soap opera "Ros na Rún" won the approval of Irish actor Andrew Scott.

Scott, who grew up in Dublin, was on O'Brien's podcast this week to plug his upcoming D-Day thriller "Pressure," in which he co-stars with fellow Irish actor Kerry Condon. 

Opening their conversation, O'Brien got straight down to business: his 2024 cameo on "Ros na Run."

"You're joking me," an understandably surprised Scott said when he learned O'Brien was on the Irish language show.

"All my lines are in Irish - well, what we used to call Gaelic - but they're all in Irish," O'Brien recalled.

When Scott asked if he had to learn the Irish lines phonetically, O'Brien jokingly replied: "They had cue cards that a horse could read."

The duo agreed that Irish is "the most insane language" and "completely crazy."

Recalling being on set, O'Brien said he asked the producer if he was going to play a "dashing" guest star, but instead learned he was playing "an idiot who was delivering balloons to the bar."

Conan O'Brien filming his cameo for the Irish language series "Ros na Rún."

Conan O'Brien filming his cameo for the Irish language series "Ros na Rún."

He said he told the producer that "before the day is out, you will fall in love with me," to which she said, "I'll fall in love with you if you get this done in half an hour."

The conversation then pivoted to O'Brien and Scott's understanding and embrace of the Irish sense of humor.

Later, O'Brien treated to Scott a viewing of his Irish language cameo, prompting hearty laughs.

"There was no way to be cool in that scene," O'Brien admitted afterward.

Scott lauded O'Brien, saying his Irish was "absolutely beautiful," adding "Bualadh bos, as we say in Irish."