Liam Neeson apparently learned the hard way about an important lesson in Catholicism: Thou shalt not publicly admit to pleasuring thyself.

During an upcoming appearance on the Conan O’Brien Needs a Friend podcast, Neeson, who grew up Catholic, admits that he stopped going to confession after an NSFW admission got him loudly shamed by a priest.

In an exclusive clip from Monday’s episode (below), Neeson begins by telling host Conan O’Brien of a time when he was 15 and a missionary visited his church in Ireland from Africa. “It was a great event when you had a missionary visiting from Africa. And he’d be there for a week and you’d go to Mass every night. And as an altar boy, I’d be serving at Mass, but to hear your confession from him it was like a big deal,” explains the actor.

Liam Neeson. KARWAI TANG/WIREIMAGE

He recalls going to do a confession with the priest, whom he describes as having a big, booming voice, and seeing a bunch of “old women just outside the confessional kneeling down and saying their prayers.”

“So we start, and I had learned how to pleasure myself at home, onto the sheets, right? I had looked up the appropriate word. I remember that… ‘Masturbate’? ‘Masturbation’? Okay.

That seems harmless enough,” he recalls. Neeson goes on to say that he started confessing to the priest things like an argument with his mom or a fight with his sister before finally admitting to… masturbating.

According to Neeson’s reenactment, the priest at this point starts shouting at him. “‘You what?!’ This guy, literally, I mean, he almost said things like, ‘The grass will grow over the palm of your hand before you’re 21! Stop that evil practice!'”

Thinking of all the old women outside who no doubt heard the entire ordeal, Neeson says he left immediately, and, “That was the last time I ever went.” As O’Brien laughingly puts it: “I think that’ll do it.”

Watch the whole story unfold in the video below and hear the full Conan O’Brien Needs a Friend interview on Monday, Aug. 28 wherever you listen to podcasts.