Murphy calls round to see his friend, Paddy, who's housebound with a broken leg.
Paddy says, "Me feet are feckin freezin. Could you nip upstairs and fetch me slippers ?".
"No bother", says Murphy and runs upstairs, where he sees Paddy's stunning, 19 year old twin daughters sitting on their beds.
"Hello, girls. Yer pa sent me up to shag you both".
"Feck off, you liar" say the girls.
Murphy says, "I'll prove it to you, and shouts down the stairs,
"Both of them, Paddy ?."
"Of course !. What's the use of just f#cking one !.".