The worst I did was call a nun "cunt".

-You said what to that nun? I repeated myself.
-I called her a cunt.
By this time the Dutch kid sitting across from me was doubled over in laughter.
-Alright dude, you gotta explain this one.
-Alright well. ‘Twas at Sunday school right? And I was talkin’ away with the lads and then, somehow, Mother Theresa, she came up. And I said: “wait a moment here, she’s guilty of extortion”. The sister said “pardon me” so I explained myself: “listen, she was takin' donations and saying it was for the children of Africa, right, and then sendin’ it to Vatican City. Then the church was deciding what to do with the money. They were only givin’ out thirty percent to dem kids in Africa”. Now if I were to go out on the street and ask people to donate money fer Africa and then only sendin’ thirty percent of it there I would be goin’ to jail man. As soon as that hit the papers boy you would see me in the cuffs.
He raised his hands up in unison as if to simulate wearing handcuffs before continuing.
-So that nun says to me “She would go places no one else would go”
As he imitated the nun his voice grew increasingly angrier and he wagged his finger menacingly in the direction of the Dutch kid.
-So I says to her: “I’ve been places no one else would go either and that doesn’t make me a Saint.” So then she got real cross and she says to me: “You get out! Right Now! Just get out!”. So I says to her “fine” and then as I’m leavin’ I turn ‘round and I says “Ya know, you are a right cunt”. Well she didn’t like that very much so she starts in screamin’ at me. Just bloody screamin’, and one of the lads wanted to 'ave at me but the others wouldn’t let ‘em. But that nun she was a right cunt though. I don’t mind the priests, they’re always all right, but the nuns though, desperate miserable women.

The previous was an actual conversation, to the best of my recollection, that I had with an Irish kid named Sean while staying in a hostel. The validity of his criticisms against Mother Theresa are unknown to me, and I in no way condone calling any nun a “cunt”, or anything else besides “sister” for that matter.