John and Mary O'Leary are a married couple who own the shop on Craggy Island (imaginatively named John and Mary's). They absolutely loathe each other and are always insulting and devising ways to maim one another. Mary is often brandishing a knife and in the episode Entertaining Father stone apparently succeeds with carrying out her threats when Ted and Dougal spot them in the hospital, John with a bloody bandage around his head and Mary in crutches. Despite this, whenever they encounter Ted or Dougal or perhaps any member of the priesthood, they act like a happily married couple. They appeared six times throughout the show's run popping up in all three seasons.
[ John and Mary prepare to sell their wares at Funland ]
John: Ya fat smelly cow!
Mary: Titface! You have a face like a pair of tits.
John: Well at least that's one pair between us.
[ Father Ted arrives to talk about his upcoming television appearance and leaves ]
John: Get those feckin' Crunchies out of the car!
Mary: Feck off!
[ John and Mary walk past Ted and Dougal in the hospital, John with a stab wound to his head and Mary with a crutch ]
Mary: Ya stupid bastard! You've really done it this time.
John: You started it, you slag!
Mary: The next time i'll finish it!
[ John and Mary notice Ted and Dougal and start being nice ]
[ John and Mary leave the hospital ]
Mary: Next time i'll friggin make sure..
John: Shut up you ol' bitch!
[ Mary knees John in the groin ]
[ John tries to pass Mary in the shop ]
John: Are you gonna stand there all day ya fat ol' bitch!
Mary: Don't talk to me like that ya big pile of shite!
[ John pushes her out of the way ]
Mary: Ya ignorant prick!
John: You watch that mouth of yours.
Mary: I'll watch nothing. [Mary brandishes a knife] I'll stick this up your arse!
[ Dougal enters to buy a pair of handcuffs ]
[ Mary is holding John's head in a bucket of water ]
Mary: You bastard!
[ Ted turns up and they start being nice ]
[ Ted leaves ]
Mary: Feckin' idiot, give it to me.
[John and Mary struggle with a shotgun]
[ Outside the shop a shot is heard ]
[ John and Mary turn up at the parochial house door with some Easter eggs for Father Ted ]
John: Don't make a show of yourself in front of him. Oh yes Father, I know Father, you're so great Father. You make me sick.
Mary:I don't know what you're talkng about. You're feckin' worse. Oh Father you're brilliant. Oh Father you should be Pope. Doesn't impress him. Makes me sick.
[ Ted answers the doorbell ]
[ John frog marches Mary to the cupboard ]
John: And you can stay in there until you learn some feckin' manners!
Mary: Let me out you bastard!
John: And i've thrown away the key. How d'ya like that ha.
[ Ted and Dougal walk into the shop, so John and Mary begin to act nice ]
[ Ted and Dougal leave ]
Mary: Well I hope you're satisfied.
John: Oh shut up.
[ Mary's fist comes through the cupboard door hitting John in the face ]