Oldie...

The roof caves in on a convent, hitting sisters Anne, Marie and Pearl in the noggin...

The three nuns appear at the pearly gates where they are met by St Peter who looks in the big black book and shakes his head with a puzzled look.

'Sister Marie. I read here that you once succumbed to temptation and gave Father O'Brien a hand job... Is that true?'

'Forgive me father, it is indeed true. I admit my transgression and deeply regret it...'

'Very well sister, I believe your sincerity. As penance, walk over to that baptismal font, wash your hands thoroughly and enter heaven. God bless you, my child'

Sister Marie does as told and enters paradise. Peter turns to the second nun and begins 'Sister Anne...' when the third nun steps up, shoving the second aside: 'No, me second!'

'Why, sister Pearl? What difference could it possibly make to you?'

'Beacause... I am absolutely not gargling with that water, after she has cleaned her ass in that font!'